Percdc Multiple Choice Questions in Est by Melvin C. Arceo
Percdc Multiple Choice Questions in Est by Melvin C. Arceo
Percdc Multiple Choice Questions in Est by Melvin C. Arceo
ELECTRONICS SYSTEMS
AND TECHNOLOGIES
By
Melvin C. Arceo
ENCODED BY:
ANDRADE, Caroline T.
GARCIA, Virginia Nonna H.
GIRAO, Edward Joseph D.
LAQUI, Louise Ruelyn J.
LORENZO, Luer Breech B.
RIVERA, Billy Joe S.
SAMONTE, Adrian A.
SANTOLLO, Dan Alvin
MULTIPLE CHOICE QUESTIONS IN
BROADCAST
ENGINEERING
Electronics Systems and Technologies
By
Melvin C. Arceo
ENCODED BY:
ANDRADE, Caroline T.
1. In stereophonic broadcast, the center frequency of each SCA subcarrier shall be kept at
all times within ____ Hz of the authorized frequency.
A. 200
B. 300
C. 400
D. 500
2. Sawtooth generator circuits produce the scanning raster, but the sync pulses are needed
for
A. Linearity
B. Timing
C. Keystoning
D. Line pairing
A. Vidicon
B. Plumbicon
C. Saticon
D. Iconoscope
A. Class A
B. Secondary
C. Class B
D. Primary
A. 30
B. 60
C. 525
D. 15,750
6. A 4.5-MHz signal which is equal to the difference between the picture and sound RF
carrier frequencies in a 6-MHz TV channel.
A. Audio frequency
B. Video frequency
C. Intercarrier frequency
D. Subcarrier frequency
7. A system where the modulated RF picture and sound carrier signals are distributed in a
cable network, instead of wireless system.
A. CCTV
B. MATV
C. CATV
D. SATV
8. A class A FM station is limited in antenna height of _____ feet above average terrain.
A. 1000
B. 2000
C. 4000
D. 5000
9. What circuit in the TV receiver is used to develop the high voltage needed to operate the
picture tube?
10. The modulated picture carrier wave includes the composite video signal as the
A. CW
B. FM
C. SSB
D. AM
A. Red
B. Cyan
C. Blue
D. Yellow-green
13. How much is the equivalent internal resistance of the electron beam with a 1.2-mA beam
current at 25 kV?
A. 48 nano ohms
B. 30 ohms
C. 20.8 mega ohms
D. 15.6 kilo ohms
14. The difference between the picture and sound carrier frequencies for channel 3 is ____
MHz.
A. 3.58
B. 64.5
C. 4.5
D. 6.75
15. Refers to the deviation of the operating frequency of a crystal oscillator from its nominal
value due to temperature variations.
A. Drift
B. Flashover
C. Frequency deviation
D. Deviation ratio
A. Definition
B. Resolution
C. Detail
D. Any of these
A. Hue signal
B. Video signal
C. Audio signal
D. Chroma signal
18. A class D FM station shall have an authorized power not exceeding _____ watts.
A. 20
B. 15
C. 10
D. 5
A. Lower-cost reception
B. Greater stability
C. Less noise, stronger signal
D. Premium cable channels
20. The width of the vertical sync pulse in the Philippine TV system is
A. 21H
B. 3H
C. H
D. 0.5H
A. Announce
B. Broadcast
C. Transmit
D. Media
A. 60
B. 262
C. 4.5
D. 30
A. Ghosting
B. Ringing
C. Fading
D. Snowing
A. Red
B. Blue
C. Yellow-green
D. Infrared
A. Pulse modulation
B. Phase modulation
C. Amplitude modulation
D. Frequency modulation
28. A video or audio signal that can be used directly to reproduce the picture and sound.
A. Baseband signal
B. Broadband signal
C. Electromagnetic wave signal
D. Modulated signal
29. Class B FM station should have an ERP not exceeding ____ kW.
A. 50
B. 40
C. 30
D. 20
30. What technique is used to permit hundreds of TV signals to share a common cable?
A. Frequency modulation
B. Mixing
C. Frequency division multiplexing
D. Time division multiplexing
A. Ringing
B. Burst
C. Damper
D. Flyback
32. In the Philippine color television system, the intercarrier frequency, in MHz, is
A. 3.58
B. 3.579545
C. 4.5
D. 45.75
33. In channel 14 (470 to 476 MHz), the 3.58-MHz color signal is transmitted at
A. 471.25 MHz
B. 473.25 MHz
C. 474.83 MHz
D. 475.25 MHz
A. Snowing
B. Flicker
C. Distortion
D. Fading
35. Beam alignment magnets for the camera tube are adjusted while rocking which control?
A. Optical focus
B. Electrical focus
C. Beam current
D. Shading
A. An FM generator
B. A circuit for detecting FM
C. A circuit for filtering two closely adjacent signals
D. An automatic bandwidth circuit
37. A system used in television field operation to make on the spot video tape recordings
using portable TV cameras and VTRs.
A. SNG
B. ENG
C. HAFC
D. MATV
38. Class B FM station shall have an authorized transmitter power not exceeding ______ kW.
A. 10
B. 100
C. 1000
D. 10000
39. The total bandwidth of an NTSC TV signal is
A. 3.58 MHz
B. 4.5 MHz
C. 6 MHz
D. 10.7 MHz
40. Referred to the oscillator signal leak through from a property neutralized amplifier such
as a master oscillator power amplifier.
A. Carrier
B. Stray signal
C. Back wave
D. Loss wave
A. 50 ohms
B. 75 ohms
C. 150 ohms
D. 300 ohms
43. The average voltage value of the 3.58-MHz modulated chrominance signal is
45. It causes the picture information to spread out or crowded at one end of the raster
compared to the opposite end.
A. Linear scanning
B. Interfaced scanning
C. Non-linear scanning
D. Retrace
46. If the camera cannot be placed far away enough to include everything in the scene,
change the lens to one with a
A. Lower f rating
B. Higher f rating
C. Longer focal length
D. Shorter focal length
A. Television video
B. Broadcasting in 535-1606 kHz
C. Single sideband HF transmission
D. Television audio
48. The amount of color in the picture or color intensity is the ______.
A. Color level
B. Chroma level
C. Saturation
D. Any of these
49. One of the early radio transmitters which produced keyed carrier generating purer
waveform than spark transmitter, used for high powered RF transmission and are limited
to radio frequency of about 500 kHz.
A. Arc transmitter
B. Hartley transmitter
C. Spark transmitter
D. Frequency transmitter
50. A technique where segments of videotape are joined by electronic erasing and recording
to create a single program.
A. Masking
B. Segmenting
C. Editing
D. Programming
51. A class C FM station has an authorized radiated power not exceeding ____watts of ERP.
A. 500
B. 750
C. 1000
D. 2000
52. The assembly around the neck of a picture tube that produces the magnetic fields that
deflect and scan the electron beams is called the
A. Shadow mask
B. Phosphor
C. Electron gun
D. Yoke
53. An odd number of lines per frame forms part of every one of the worlds TV systems.
This is
54. The difference between the sound carrier and the color signal is
A. 4.5 MHz
B. 1.25 MHz
C. 0.92 MHz
D. 0.25 MHz
A. Beam-landing adjustment
B. Degaussing
C. Internal blanking adjustment
D. Background control
56. Which of the following camera tubes uses load oxide for the photoconductive target
plate?
A. Vidicon
B. Plumbicon
C. Saticon
D. Image orthicon
A. Audio signal
B. Video Signal
C. Intercarrier signal
D. Color signal
A. 1000
B. 500
C. 250
D. 100
60. The HV anode supply for the picture tube of a TV receiver is generated in the
A. Mains transformer
B. Vertical output stage
C. Horizontal output stage
D. Horizontal deflection oscillator
62. Which system can be used for both recording and playback?
A. CED
B. VHD
C. Laser disk
D. VHS
A. Cyan
B. Yellow
C. Green
D. Blue
64. It is used around the phosphor dots to make a darker black which improves contrast in the
picture.
A. Black masking
B. Convergence adjustment
C. Shadow masking
D. Color purity adjustment
65. A lens lower f rating is ____ lens that allows more light input.
A. Slower
B. Wider
C. Narrower
D. Faster
66. Picture frames are repeated at the rate of ____ per second.
A. 30
B. 60
C. 45
D. 50
67. The effective radiated power of a class A FM station should not exceed _____ kW.
A. 125
B. 30
C. 10
D. 1
A. Interface ratio
B. Maximum horizontal deflection
C. Aspect ratio
D. Ratio of the two diagonals
A. Color-under
B. Zero guard bands
C. FM luminance signal
D. Long-play tapes
70. It is a special camera tube with a test pattern in the image plate.
A. Vidicon
B. Monoscope
C. Oscilloscope
D. Iconoscope
71. The number of lines scanned per frame in the raster on the picture tube screen is
A. 525
B. 262
C. 20
D. 10
72. One of the following is a high powered RF ac basic transmitter that has two or more
stages, the oscillator stage which determines the frequency of operation and RF amplifier
stage or stages that develop the high power output. The purpose of which is to develop a
good frequency stability.
A. MOPA
B. Hartley
C. Alexanderson
D. Goldsmith
A. Black burst
B. Generator lock video
C. Composite video
D. Non-composite video
A. Brightness
B. Contrast
C. Chroma
D. Hue
A. HF
B. UHF
C. MF
D. VHF
76. The I and Q composite color signals are multiplexed onto the picture carrier by
modulating a 3.58 MHz subcarrier using
A. FM
B. PM
C. DSB AM
D. Vestigial sideband AM
A. Tape speed
B. Writing speed
C. Reel rotation
D. Tape tension
79. How ho you eliminate radio frequency variation of an oscillator transmitter caused by its
supply voltage?
80. The composite video signal includes the camera signal with the following except
A. Picture information
B. Sync pulses
C. Blanking pulses
D. Camera signal
81. A lens has an 8-cm focal length and 4-cm diameter. Its f rating is
A. 2
B. 4
C. 8
D. 32
82. Which of the following is a possible cause for an abrupt frequency variation in a self-
excited transmitter oscillator circuits resulting a poor frequency stability to hold a
constant frequency oscillation?
83. How long does it take to scan 2 picture elements when 400 are scanned in 50
microseconds?
A. 25 microsec
B. 0.25 microsec
C. 2.5 microsec
D. 0.5 microsec
84. Anode voltage for the picture tube, developed from the output of the horizontal deflection
circuit.
A. Yoke voltage
B. Flyback voltage
C. Aquadag voltage
D. Tube voltage
A. 400 kHz
B. 800 kHz
C. 600 kHz
D. 200 kHz
A. RGB
B. Color subcarrier
C. Q and I
D. Luminance Y
A. 6
B. 7
C. 14
D. 23
A. Red
B. Yellow
C. Green
D. Blue
90. It is the light flux intercepted by one-foot-square surface that is one foot from one-
candlepower source.
A. Candela
B. Footcandle
C. Lux
D. Lumens
91. Refers to the possible cause for an abrupt frequency variations in a self-excited
transmitter oscillator circuit resulting to a poor frequency stability to hold a constant
oscillator.
92. It is the difference in intensity between the black parts and white parts of the picture.
A. Brightness
B. Hue
C. Contrast
D. Illumination
A. 4.5 MHz
B. 10.7 MHz
C. 41.25 MHz
D. 45.75 MHz
95. The circuit separates sync pulse from the composite video waveform is
96. In the CED system, the disk capacitance varies with the
A. Pit depth
B. Disk size
C. Speed of rotation
D. Wavelength of the scanning light
97. The final power amplifier in an FM transmitter usually operates class _____
A. AB
B. C
C. B
D. A
98. In a picture tube, it is the total angle that the beam can be deflected without touching the
sides of the envelope.
A. Screen angle
B. Tube angle
C. Picture angle
D. Deflection angle
A. Flyback
B. Synchronization
C. Blanking
D. Scanning
A. 455 kHz
B. 10.7 MHz
C. 11.4 MHz
D. 12.5 MHz
A. Frequency instability
B. Non-portable
C. Heating effect
D. Bulky
103. The carrier transmitted 1.25 MHz above the bottom frequency in a Philippine TV
channel is the
A. Sound carrier
B. Chroma carrier
C. Intercarrier
D. Picture carrier
104. In camera tubes, it means that the old image remains too long after the picture
information on the target plate has changed.
A. Light lag
B. Switch lag
C. Image lag
D. Camera lag
A. 1.6 MHz
B. 0.5 MHz
C. 1.0 MHz
D. 1.3 MHz
106. Class of FM station where its authorized power should not exceed 15 kW.
A. Class A
B. Class B
C. Class C
D. Class D
107. What is the name of the solid state imaging device used in TV cameras that
converts the light in a scene into an electrical signal?
A. CCD
B. Phototube matrix
C. Vidicon
D. MOSFET array
108. The signals sent by the transmitter to ensure correct scanning in the receiver is
called
A. Sync
B. Chroma
C. Luminance
D. Video
109. What signals are transmitted by a SSBSC transmitter when no modulating signal
is present?
110. The second IF value for color in receivers, for any station, is
A. 0.5 MHz
B. 1.3 MHz
C. 3.58 MHz
D. 4.5 MHz
111. In the frame for which interfaced scanning is used, alternate lines are skipped
during vertical scanning because
A. 0.2 microampere
B. About 200 microampere
C. 8 milliampere
D. 800 milliampere
113. The smallest are of light or shade in the image is a picture element called
A. Chroma
B. Hue
C. Contrast
D. Pixel
114. An entry of the time the station begins to supply power to the antenna and the
time it stops.
115. What type of circuit is used to modulate and demodulate the color signals?
A. Phase-locked loop
B. Differential peak detector
C. Quadrature detector
D. Balanced modulator
116. This is referred to as a fixed radio station that broadcast program material from
audio to transmitter by radio link.
117. Indicate which of the following frequencies will not be found in the output of a
normal TV receiver tuner.
A. 4.5 MHz
B. 41.25 MHz
C. 45.75 MHz
D. 42.17 MHz
118. In all standard television broadcast channels , the difference between the picture
and sound carrier frequencies is
A. 0.25 MHz
B. 1.25 MHz
C. 4.5 MHz
D. 6 MHz
119. It is caused by phase distortion for video frequencies of about 100 kHz and lower.
A. Streaking
B. Snowing
C. Ringing
D. Fading
A. CCU
B. ENG camera
C. SEG
D. Sync generator
121. A picture has 400 horizontal and 300 vertical picture elements. What is the total
number of details in the picture?
A. 120,000
B. 700
C. 0.75
D. 100
122. After the IF stages have been aligned, the next stage to align in FM receiver is
A. Local oscillator
B. Limiter stage
C. RF amplifier
D. Mixer stage
A. Sync pulses
B. Quadrature modulation
C. 4.5-MHz intercarrier sound
D. 3.58-MHz color burst
124. The interfering beat frequency of 920 kHz is between the 3.58-MHz color
subcarrier and the
A. Camera tube
B. Picture tube
C. Anode tube
D. Cathode tube
126. The frequency spectrum of the stereophonic FM signal.
A. 67 kHz
B. 59.5 to 74.5 kHz
C. 19 to 38 kHz
D. 30 to 53 kHz
A. Horizontal blanking
B. Vertical blanking
C. The serrations
D. The horizontal retrace
128. Which signal has color information for 1.3 MHz bandwidth?
A. I
B. Y
C. R-Y
D. B-Y
129. It is the distance from the center of the lens of the camera to the point at which
parallel rays from a distant object come to a common focal point.
A. Focal length
B. Latus rectum
C. Major axis
D. Minor axis
A. Direct
B. Indirect
C. Insertion
D. All of these
131. The picture and sound carrier frequencies in a TV receiver IF are respectively.
A. 3
B. 6
C. 7
D. 9
134. One-half line spacing between the start positions for scanning even and odd fields
produces
A. Linear scanning
B. Line pairing
C. Fishtailing
D. Exact interlacing
A. A black-and-white camera
B. Plumbicon
C. A single-tube color pickup
D. A saticon
136. A signal in which the sum of all signals which frequency-modulates the main
carrier.
137. What is the total number of interlaced scan lines in one complete frame of a
NTSC Philippine TV signal?
A. 262
B. 525
C. 480
D. 625
138. The video voltage applied to the picture tube of a television receiver is fed in
A. 0
B. 1
C. 3
D. 6
140. In color television, it is made to maintain neutral white from low to high levels of
brightness.
141. Average power of a radio transmitter supplied to the antenna transmission line by
a transmitter during one radio frequency cycle taken under the condition or no
modulation.
A. 525
B. 262
C. 15,750
D. 30
143. The ratio of the actual frequency swing to the frequency swing defined as 100
percent modulation, expressed in percentage.
A. Modulation index
B. Deviation ration
C. Maximum deviation
D. Percentage modulation
145. How many TV fields are recorded on one slant track of tape?
A. 1
B. 2
C. 4
D. 60
A. 15
B. 13
C. 10
D. 20
147. The width of a vertical sync pulse with its serrations includes the time of
148. A low-contrast picture in which white seems flat and lacking in detail suggests
149. The product of the transmitter power multiplied by the antenna power gain of the
antenna field gain squared.
A. Field intensity
B. Field gain
C. ERP
D. Electric field strength
150. What keeps the scanning process at the receiver in step with the scanning in the
picture tube at the receiver?
A. Nothing
B. Sync pulses
C. Color burst
D. Deflection oscillators
A. 31,500
B. 15,700
C. 262
D. 525
A. Arc
B. Spark
C. Alexanderson
D. High end
A. Alpha
B. Beta
C. Gamma
D. Sigma
154. Color picture tubes have ______ guns for its phosphors.
A. 1
B. 2
C. 3
D. 4
155. The FM broadcast band is divided into _____ channels are suggested by KBP.
A. 200
B. 100
C. 50
D. 25
156. The output of the vertical amplifier, applied to the yoke in a TV receiver, consists
of
A. Direct current
B. Amplified vertical sync pulse
C. A sawtooth voltage
D. A sawtooth current
A. 67 kHz
B. 59.5 kHz to 74.5 kHz
C. 19 kHz to 38 kHz
D. 30 kHz to 53 kHz
158. What is the video frequency response corresponding to the horizontal resolution
of 200 lines?
A. 4 MHz
B. 1.5 MHz
C. 4.5 MHz
D. 2.5 MHz
A. 0.4545
B. 1.0
C. 1.4
D. 2.2
160. It is the instantaneous departure of the frequency of the emitted wave from the
center frequency resulting from modulation.
A. Deviation
B. Frequency swing
C. Phase shift
D. Deviation ratio
161. If a TV sound transmitter has a carrier frequency of 197.75 MHz, the picture
carrier is
A. 191.75 MHz
B. 193.25 MHz
C. 202.25 MHz
D. 203.75 MHz
A. 262
B. 525
C. 30
D. 60
163. What is the best site of an AM broadcast transmitter?
A. Marshy land
B. Dry land
C. Highly elevated
D. Average terrain
164. What is the hue of a color 90 degrees leading sync burst phase?
A. Yellow
B. Cyan
C. Blue
D. Orange
165. The two black conductive coatings of picture tubes are made up of
A. Phosphor
B. Aquadag
C. Cavity
D. Nickel
A. 10 kW
B. 20 kW
C. 40 kW
D. 30 kW
A. Equalize the change in the integrator before the start of vertical retrace
B. Help vertical synchronization
C. Help horizontal synchronization
D. Simplify the generation of the vertical sync pulse
A. CED
B. VHD
C. Betamax
D. VLP
169. Weak emission from one cathode in a tricolor picture tube causes
A. A weak picture
B. A long warmup time
C. A color imbalance in the raster and picture
D. All of these
170. In AM broadcast, the current carrier shift at any percentage of modulation shall
not exceed
A. 5%
B. 15%
C. 20%
D. 2.5%
171. Indicate which voltages are not found in the output of a normal monochrome
receiver video detector.
A. Sync
B. Video
C. Sweep
D. Sound
A. Horizontal deflection
B. Distortions
C. Linear scanning
D. Flicker
A. +/- 10 Hz
B. +/- 20 Hz
C. +/- 25 Hz
D. +/- 75 Hz
174. How much illumination in lux a 400-candlepower make that is 3 meters from the
surface?
A. 133.3
B. 1200
C. 200
D. 44.4
A. I
B. Q
C. Y
D. R-Y
A. 1
B. 2
C. 3
D. 8
177. For television, the maximum deviation of the FM sound signal in kHz.
A. 10
B. 25
C. 75
D. 100
A. Y
B. Q
C. R
D. I
179. Emission outside of the assigned channel, as a result of the modulation process.
A. Overmodulation
B. Spurious emission
C. Out-of-band emission
D. In band emission
180. Determine which of the following is not part of RF section of a radio transmitter.
A. Master oscillator
B. Buffer amplifier
C. AF voltage amplifier
D. Frequency amplifier
181. The power of any conducted spurious emission shall be attenuated below the
maximum level of carrier frequency in accordance with the following formula:
A. Color
B. Contrast
C. Brightness
D. Hue
183. In the IRE scale for the composite video signal, what is the number of IRE units
for sync?
A. 7.5
B. 92.5
C. 40
D. 10
184. As prescribed by the technical standards for Cable Television operation and in
order to be compatible for any value added services in the future, Trunk cable should
have a minimum diameter of _______.
A. 0.25 inch
B. 0.5 inch
C. 0.75 inch
D. 1.0 inch
185. Compared with 100 percent saturation, the desaturated color have
186. What is the practical baseband frequency for the color video signal?
A. 1 MHz
B. 2 MHz
C. 0.2 MHz
D. 0.5 MHz
187. What is the diagonal screen size for the 19CP4 picture tube?
A. 21
B. 23
C. 4
D. 19
188. What is the phase angle between B Y and R Y?
A. 180 deg
B. 45 deg
C. 90 deg
D. 270 deg
189. How many gray scale steps are in the EIA test pattern in television?
A. 10
B. 40
C. 50
D. 15
A. Direct current
B. Pulsed current
C. Alternating current
D. Any of these
A. Black
B. Dark gray
C. White
D. Light gray
192. What is the phase difference between the color sync burst and the B Y video?
A. 180 deg
B. 45 deg
C. 90 deg
D. 270 deg
A. Yellow-green
B. Red
C. Blue
D. Orange
A. HSC
B. HAFC
C. HFC
D. HAC
195. What is the typical anode voltage for a 25-inch color picture tube?
A. 3 kV
B. 20 kV
C. 10 kV
D. 30 kV
196. In television, what is the phosphor number for monochrome picture tube?
A. P4
B. P21
C. P22
D. P3
A. Red
B. Green
C. Yellow
D. Blue
A. 1 MHz
B. 3 MHz
C. 2 MHz
D. 4 MHz
199. The minimum FM broadcast transmitter power in metro manila and metro cebu is
A. 25 kW
B. 10 kW
C. 1 kW
D. 30 kW
A. 10 kW
B. 20 kW
C. 15 kW
D. 5 kW
201. What are the frequency limits of the standard AM broadcast band?
A. 30 kHz
B. 25 kHz
C. 15 kHz
D. 200 kHz
203. The following are designations of service areas of AM broadcast station, except:
A. Primary
B. Secondary
C. Tertiary
D. Intermittent
A. Daytime
B. Night time
C. Mid-day
D. Experimental period
A. Attenuator
B. Gain control
C. Fader
D. Any of these
207. The highest peaks of modulation in AM should be held between what two
percentages?
A. 85-100%
B. 65-70%
C. 50-75%
D. 75-90%
208. What is the name of the second transmitter used when a station operates 24 hours
a day?
A. Alternate
B. Reserve
C. Spare
D. Diversity
A. Announcer
B. Disk jockey
C. Engineer
D. All of these
A. Communication
B. Talk-back
C. Respond
D. Remote talk
212. What is the attenuator which controls the the output of the program amplifier
called?
213. The following are important operational requirements during a broadcast, except:
A. Timing
B. Modulation
C. Fidelity
D. AF amplitude
214. What are the names of two unbalanced pads used in broadcasting?
A. T and L
B. K and P
C. R and I
D. H and L
217. What device is used to make up for the high-frequency losses in long AF lines?
A. Signal booster
B. Noise suppressor
C. Line equalizer
D. Compander
A. Licensed power
B. Sideband power
C. Audio power
D. Harmonic power
A. Mid-day
B. Daytime
C. Night time
D. Experimental period
A. 3%
B. 4%
C. 5%
D. 6%
A. Omnidirectional antennas
B. Directive antennas
C. High gain antennas
D. Any of these
223. Within what limits must the antenna current ratios of a directional antenna be
held?
A. 3%
B. 5%
C. 4%
D. 1%
A. Frequency
B. Modulation
C. Fidelity
D. Carrier
225. What monitor may also give an indication of carrier amplitude regulation?
A. Modulation
B. Carrier
C. Fidelity
D. Frequency
226. What device can give the most accurate instantaneous peak-of-modulation
indications?
A. Spectrum analyzer
B. Fourier analyzer
C. CRT oscilloscope
D. Frequency probe
A. Identification
B. Program description
C. Sponsors and network name
D. All of these
A. Any of these
B. Antenna current checks
C. Meter replacements
D. Light inspection and experimental period operation
230. What is the minimum time broadcast station logs must be held?
A. One year
B. Two years
C. Three years
D. Five years
231. What class operator has no restrictions on technical work in a broadcast station?
A. 1st phone
B. 2nd phone
C. 3rd phone
D. 4th phone
232. What classes of operators are restricted on technical work in a broadcast station?
A. 3rd phone
B. 2nd phone
C. 4th phone
D. 2nd and 3rd phone
233. If improper transmitter indications are given at the remote-control point, what
should be done?
A. First phone operator to transmitter
B. Second phone operator to transmitter
C. Third phone operator to transmitter
D. Fourth phone to transmitter
A. Quarter of an hour
B. Half an hour
C. On the hour
D. On the day
A. Tower
B. Modulators
C. Transmitter
D. Receiver
A. Operating desk
B. Operating position
C. Operating console
D. Anywhere
237. What device is usually used today to measure the frequency of a broadcast
station?
A. Multivibrators
B. Counter
C. Ripper
D. Wave meter
A. Weekly
B. Daily
C. Monthly
D. Yearly
A. Ruby
B. Gamet
C. Emerald
D. Diamond
A. Constant speed
B. Less vibration
C. Rumble
D. All of these
A. 0.5 inch
B. 0.75 inch
C. 0.125 inch
D. 1 inch
A. Supersonic
B. Subsonic
C. Ultrasonic
D. Infrasonic
A. 20 in/sec
B. 15 in/sec
C. 10 in/sec
D. 5 in /sec
A. All of these
B. 150 ohms
C. 250 ohms
D. 600 ohms
A. Maintenance log
B. Program log
C. Operating log
D. Logging log
A. Vidicon
B. Iconoscope
C. Image orthicon
D. Kinescope
A. Vidicon
B. Iconoscope
C. Image orthicon
D. Kinescope
A. Vidicon
B. Iconoscope
C. Image orthicon
D. Kinescope
A. Trapezoidal
B. Sawtooth
C. Trigger
D. Square
253. If the pulse peak is 100% modulation, what is the blanking level?
A. 25%
B. 50%
C. 65%
D. 75%
254. What device allows one camera to accept pictures from three or more projectors?
A. Film multipliers
B. Film demultiplexers
C. Film multiplexers
D. Film acceptor
255. What is the order of scanning four successive motion-picture frames for TV?
A. 3,2,3,2
B. 2,3,2,3
C. 2,2,3,3
D. 3,3,2,2
256. From the low-frequency end of a channel, what is the visual carrier frequency?
A. 3.58 MHz
B. 0.25 MHz
C. 1.25 MHz
D. 4.5 MHz
A. RF
B. Mixer
C. IF
D. Oscillator
A. 300 ohms
B. 150 ohms
C. 50 ohms
D. 100 ohms
A. Cascade
B. Darlington
C. Cascade
D. Shunt
A. Aural IF
B. Video
C. Blanking
D. Any of these
262. When coupling from a sync separator, what is used to obtain the horizontal sync
pulses?
A. Integrator
B. Corrector
C. Differentiator
D. Separator
263. When coupling from a sync separator, what is used to obtain the vertical sync
pulses?
A. Integrator
B. Corrector
C. Differentiator
D. Separator
264. The type of active device used in horizontal output stages, except:?
A. Vacuum tube
B. FET
C. BJT
D. SCR
265. What should be produced by weak blue, weak green, and weak red signals on a
color CRT?
A. White
B. Shade
C. Gray
D. Off white
A. One
B. Two
C. Three
D. Four
A. Combiner
B. Multiplexer
C. Integrator
D. Mixer
A. R
B. Q
C. I
D. Y
A. 0
B. 1
C. 2
D. 1.5
A. 1
B. 2
C. 0
D. 2.5
A. One
B. 0.5
C. Zero
D. 1.5
273. If the blue dot is always at the bottom of a triad, what position must the blue gun
always have?
A. Top
B. Left side
C. Right aside
D. Center
A. 1
B. 2
C. 3
D. 4
A. 1
B. 2
C. 3
D. 4
MULTIPLE CHOICE QUESTIONS IN
TRANSMISSION LINES
Electronics Systems and Technologies
By
Melvin C. Arceo
ENCODED BY:
ANDRADE, Caroline T.
1. Category of media with some form of conductor that provides a conduit in which
electromagnetic signals are contained.
A. Guided
B. Balanced
C. Unguided
D. Unbalanced
A. Transmission Lines
B. Antenna
C. Frequency allocations
D. Load
3. Calculate the characteristic impedance for a line that exhibits an inductance of 4 nH/m
and 1.5pF/m
A. 36.6 ohms
B. 51.6 ohms
C. 22 ohms
D. 24.5 ohms
A. Guided
B. Balanced
C. Unguided
D. Unbalanced
6. It is a metallic conductor system used to transfer electrical energy from one point to
another using electrical current flow.
A. Transmitter
B. Multiplexers
C. Receiver
D. Transmission line
A. Transverse
B. Longitudinal
C. Reverse
D. Perpendicular
8. Calculate the capacitance per meter of a 50-ohm load cable that has an inductance of 55
nH/m.
A. 13 pF
B. 18 pF
C. 20 pF
D. 22 pF
A. 0
B. 1
C. 2
D. Infinity
10. A kind of wave where the direction is displacement is perpendicular to the direction of
propagation.
A. Transverse
B. Longitudinal
C. Reverse
D. Perpendicular
12. Electromagnetic waves that travel along a transmission line from the source to the load.
A. Reverse waves
B. Transverse waves
C. Incident waves
D. Longitudinal waves
13. Electromagnetic waves that travel from the load back toward the source.
A. Incident waves
B. Transverse waves
C. Forward waves
D. Reflected waves
15. Determine the surge impedance for a parallel wire, air dielectric with a ratio of the
spacing between conductors and the diameter of 3
A. 250 ohms
B. 210 ohms
C. 180 ohms
D. 215 ohms
A. Wavelength
B. Amplitude
C. Period
D. Frequency
A. Wavelength
B. Amplitudes
C. Period
D. Frequency
18. Classification of transmission line where both conductors carry current; one conductor
carries the signal, the other conductor is the return path
A. Capacitor
B. Inductor
C. Series resonant circuit
D. Parallel resonant circuit
20. What is the characteristic impedance of a coaxial line, air dielectric with a ratio of the
diameter of the outer and inner conductor equal to 1.5?
A. 24.3 ohms
B. 25.6 ohms
C. 13.2 ohms
D. 18 ohms
21. Currents that flow in opposite direction in a balanced wire pair is called
A. Longitudinal currents
B. Reverse circuit currents
C. Transverse circuit currents
D. Metallic circuit currents
22. Currents that flow in same direction in a balanced wire pair is called
A. Longitudinal currents
B. Reverse circuit currents
C. Transverse circuit currents
D. In-phase currents
23. A circuit device used to connect a balanced transmission line to an unbalanced load
A. Slotted lines
B. Stub
C. Balun
D. Quarterwave lines
24. The most common type of balun used in relatively high frequency
A. Narrowband
B. Choke
C. Sleeve
D. All of these
25. A pattern of voltage and current variations along the transmission line not terminated in
its characteristic impedance is called
A. An electric fluid
B. Radio waves
C. Standing waves
D. A magnetic field
26. A type of parallel-conductor transmission lines consists of simply of two parallel wires,
closely-spaced and separated by air.
A. Twisted pair
B. Open-wire lines
C. Coaxial cables
D. Twin pair
27. A type of parallel-conductor transmission lines which is essentially the same as open-wire
transmission line except that the spacers between the conductors are replaced with a
continuous solid dielectric that ensures uniform spacing along the entire cable
A. Twisted pair
B. Open-wire lines
C. Coaxial cables
D. Twin lead
A. AWG 16 to AWG 26
B. AWG 14 to AWG 25
C. AWG 10 to AWG 20
D. AWG 12 to AWG 28
29. What is the characteristic impedance of a coaxial line, polyethylene dielectric with the
ratio of the diameter of the outer and the inner conductor of 2.5?
A. 43.5 ohms
B. 23.4 ohms
C. 36.2 ohms
D. 29.8 ohms
30. In AWG, the higher the wire gauge ______
31. Type of twisted pair wire cable that consists of two copper wires where each wire is
separately encapsulated in PVC insulation.
34. A delay line using RG-8A/U cable is to exhibit a 5-ns delay. Calculate the required length
of the cable.
A. 4.57 ft
B. 1.23 ft
C. 6.2 ft
D. 3.4 ft
A. Level 1 or Cat 1
B. Level 3 or Cat 3
C. Level 2 or Cat 2
D. Cat 4
37. An antenna is being fed by a properly terminated two-wire transmission line. The current
in the line at the input end is 3A. The surge impedance of the line is 500 ohms. How
much power is being supplied to the line?
A. 3.1 kW
B. 2.5 kW
C. 1.6 kW
D. 4.5 kW
38. Level or Category of UTP cable which was developed for IEEE 802.5 token ring local
area networks operating at a transmission rates of 4Mbps
A. Level 1 or Cat 1
B. Level 3 or Cat 3
C. Level 2 or Cat 2
D. Cat 4
39. If the period of one complete cycle of a radio wave is 0.000001 s, what is the
wavelength?
A. 300 m
B. 200 m
C. 100 m
D. 400 m
40. If the two towers of a 950-kHz antenna are separated by 120 electrical degrees, what is
the tower separation in feet?
A. 231 ft
B. 235 ft
C. 176 ft
D. 345 ft
41. Category of UTP used for virtually any voice or data transmission rate up to 16 Mbps,
has a minimum of 3 turns per inch.
A. Category 5e
B. Category 4
C. Category 5
D. Category 3
42. The mismatch between the antenna and transmission line impedances cannot be corrected
for by
43. Category of UTP that was designed for data transmission rates up to 20 Mbps
A. Category 5e
B. Category 4
C. Category 5
D. Category 3
44. Variation of CAT5 cables that are intended for data transmission rates up to 250 Mbps
A. Category 5e
B. Category 2
C. Category 6
D. Category 3
45. A type of twisted-pair wherein its wires and dielectric are enclosed in a conductive metal
sleeve called a foil.
A. STP
B. Twin lead
C. UTP
D. Unshielded Twin lead
46. It is the name given to the area between the ceiling and the roof in a single-story building
or between the ceiling and the floor of the next higher level in a multistory building.
A. Attic
B. Rooftop
C. Plenum
D. Ceiling
48. In a transmission line, it refers to the woven stranded mesh or braid that surround some
types of coaxial cables
A. Grounding
B. Shielding
C. Degaussing
D. Any of these
49. A coaxial cable with one layer of foil insulation and one layer of braided shielding.
A. Backup shielding
B. Temporary shielding
C. Dual shielding
D. Interference shielding
A. Tuned circuits
B. Antennas
C. Insulators
D. Resistors
51. A coaxial cable with two layers of foil insulation and two layers of braided shielding.
A. Quad shielding
B. Double shielding
C. Triple shielding
D. Shielding
52. A type of coaxial cable that has a tubular outer conductor surrounds the center conductor
coaxially and the insulating material is air
53. If the length of an open-circuited stub is less than quarter-wavelength but greater than 0,
the stub behaves as
A. Inductor
B. Capacitor
C. Resistor
D. Complex
54. Type of coaxial cable where the outer conductor is braided, flexible, and coaxial to the
center conductor.
A. 0.685
B. 1
C. 1.46
D. 2.92
56. Defined as the impedance seen looking at an infinitely long line or the impedance seen
looking into a finite length of the line that is terminated in a purely resistive load with the
resistance equal to the characteristic impedance of the line.
A. Input impedance
B. Surge impedance
C. Output impedance
D. Circuit impedance
57. Determine the characteristic impedance for an air dielectric two-wire parallel
transmission line with a D/r ratio of 12.22
A. 150 ohms
B. 120 ohms
C. 75 ohms
D. 300 ohms
58. Determine the characteristic impedance for an RG-59A coaxial cable with the following
specifications: d=0.025 inches, D=0.15 inches, and dielectric constant of 2.23
A. 120 ohms
B. 72 ohms
C. 150 ohms
D. 75 ohms
59. Determine the characteristic impedance for an RG-59A coaxial cable with the following
specifications: L=0.118 uH/ft and C=21 pF/ft
A. 150 ohms
B. 72 ohms
C. 75 ohms
D. 100 ohms
60. It is used to express the attenuation or signal loss and the phase shift per unit length of the
transmission line.
A. Propagation coefficient
B. Propagation constant
C. Propagation factor
D. Any of these
61. For matched condition, what is the relationship of load and characteristic impedance?
A. Greater than
B. Less than
C. Equal
D. Impossible to say
A. Velocity factor
B. Velocity propagation
C. Index of refraction
D. Phase delay
A. Permittivity
B. Insulation constant
C. Dielectric constant
D. Resistivity
64. For a given length of RG 8A/U coaxial cable with distributed capacitance of 96.6 pF/m, a
distributed inductance of 241.56 nH/m, and a relative dielectric constant of 2.3, determine
the velocity of propagation
65. For a given length of RG 8A/U coaxial cable with distributed capacitance of 96.6 pF/m, a
distributed inductance of 241.56 nH/m, and a relative dielectric constant of 2.3, determine
the velocity factor
A. 1.2
B. 0.66
C. 0.7
D. 0.5
66. If the length of an open-circuited stub is greater than quarter-wavelength but less than
half-wavelength, the stub behaves as
A. Inductor
B. Capacitor
C. Resistor
D. Complex
68. How is the time delay calculated in a coaxial cables with a dielectric constant of 0.66?
A. 0.56 sec
B. 0.67 sec
C. 0.45 sec
D. 1.2 sec
A. 100 MHz
B. 164 MHz
C. 300 MHz
D. 328 MHz
70. When current flows through a conductor, the loss introduced as a function of resistance
and current is called _______
A. Inductance loss
B. Conductor loss
C. Voltage loss
D. Skin effect
71. For maximum absorption of power at the antenna, the relationship between the
characteristic impedance of the line Zo and the load impedance ZL should be
A. Zo = ZL
B. Zo > ZL
C. Zo < ZL
D. Zo = 0
A. Impedance ratio
B. Susceptance ratio
C. Resistance ratio
D. Conductance ratio
73. The difference in potential between two conductors of a metallic transmission line causes
______.
A. Conductor loss
B. Dielectric heating
C. Radiation loss
D. Corona
74. If the length of a short-circuited stub is greater than quarter-wavelength but less than half-
wavelength, the stub behaves as
A. Inductor
B. Capacitor
C. Resistor
D. Complex
75. If the separation between the conductors in a metallic transmission line is an appreciable
fraction of a wavelength, the electrostatic and electromagnetic fields that surround the
conductor cause the line to act as if it were an antenna and transfer energy to any nearby
material. This energy radiated is called ______.
A. Radiation loss
B. Power loss
C. Coupling loss
D. Corona
76. The minimum voltage along a transmission line is 260 V, while the maximum is 390 V.
The SWR is
A. 0.67
B. 1.0
C. 1.2
D. 1.5
77. It occurs whenever a connection is made to or from a transmission line or when two
sections of transmission line are connected together
A. Power loss
B. Coupling loss
C. Radiation loss
D. Resistance loss
A. 50 ohms
B. 75 ohms
C. 120 ohms
D. 300 ohms
79. It is a luminous discharge that occurs between the two conductors of a transmission line
when the difference in potential between them exceeds the breakdown voltage of a
dielectric insulator.
A. Resistance loss
B. Corona
C. Radiation loss
D. Power loss
A. Reflected voltage
B. Standing wave ratio
C. Incident voltage
D. Reflection voltage
81. Voltage that propagates from the load towards the source
A. Reflected voltage
B. Standing wave ratio
C. Reflection coefficient
D. Incident voltage
A. Flat
B. Resistive
C. Non resonant line
D. Any of these
83. It is a vector quantity that represents the ratio of reflected voltage to incident voltage or
the reflected current and the incident current
A. Reflection coefficient
B. Reactive load diagram
C. Standing wave ratio
D. Traveling waves
84. With a mismatched line, two electromagnetic waves traveling in opposite direction,
present on the line on the same time.
85. The two traveling waves sets up an interference pattern called _______.
86. It is defined as the ratio of the maximum voltage to the minimum voltage or the
maximum current to the minimum current of a standing wave in a transmission line.
87. For a transmission line with an incident voltage of 5V and a reflected voltage of 3V,
determine the reflection coefficient.
A. 0.4
B. 0.6
C. 0.5
D. 0.7
88. A ratio expressing the percentage of incident voltage reflected on a transmission line is
known as the
A. Velocity factor
B. Standing wave ratio
C. Reflection coefficient
D. Line efficiency
A. Half wavelength
B. Quarter wavelength
C. Full wavelength
D. Three-eights of a wavelength
90. The characteristic impedance of a transmission line does not depend upon its
A. Length
B. Conductor diameter
C. Conductor spacing
D. None of these
91. ______ are used to match transmission lines to purely resistive loads whose resistance is
not equal to the characteristic impedance of the line.
A. Stub
B. Slotted lines
C. Quarter-wavelength transformer
D. Short circuited lines
A. TDR
B. Wattmeter
C. Voltmeter
D. SWR meter
94. A pulse is transmitted down a cable that has a velocity of propagation of 0.8c. The
reflected signal is received 1us later. How far down the cable is the impairment?
A. 240 m
B. 15 m
C. 60 m
D. 120 m
95. Using TDR, a transmission line impairment is located 3000m from the source. For a
velocity propagation of 0.9c, determine the time elapsed from the beginning of the pulse
to the reception of the echo
A. 11.11 us
B. 10.12 us
C. 22.22 us
D. 21.14 us
96. A flat conductor separated from a ground plane by an insulating dielectric material
A. Stripline
B. Waveguide
C. Microstrip
D. Coaxial cable
A. Stripline
B. Waveguide
C. Microstrip
D. Coaxial cable
98. Indicate the false statement. The SWR on a transmission line is infinity; the line is
terminated in
A. A short circuit
B. A complex impedance
C. An open circuit
D. A pure reactance
A. A short-circuited stub
B. An open-circuited stub
C. A quarter-wave line
D. A half-wave line
A. 0
B. 0.5
C. 1
D. Infinity
105. Short circuited stubs are preferred to open-circuited stub because the latter are
A. Balun
B. Broadband directional coupler
C. Double stub
D. Single stub of adjustable position
A. Slotted line
B. Balun
C. Directional coupler
D. Quarter-wave transformer
110. If the length of a short-circuited stub is less than a quarter-wavelength but greater than
0, the stub behaves as
A. Inductor
B. Capacitor
C. Resistor
D. Complex
111. The depth of penetration of current density resulting from skin effect
A. Skin depth
B. Wire depth
C. Line depth
D. Medium depth
114. A transmission line containing of two conductors that have equal resistance per unit
length
A. Unbalanced line
B. Open-wire line
C. Balanced line
D. Coaxial cable
A. Inductance
B. Capacitance
C. Physical dimension
D. Length
116. Category of UTP that was designed for data transmission rates up to 20 Mbps
A. Category 5e
B. Category 4
C. Category 5
D. Category 3
117. Level 2 or category 2 UTP cables comply with IBMs _______ specification.
A. Type 1
B. Type 3
C. Type 2
D. Type 4
118. Level 3 or Category 3 UTP cables should have at least ____ twist per inch.
A. 1
B. 2
C. 3
D. 4
119. Which of the following is NOT a color code for Category 5 UTP?
A. Cat 5e
B. Cat 7
C. Cat 6
D. Cat 8
122. A short-circuited transmission line more than quarter-wavelength long but shorter than
half wavelength is equivalent to _______.
A. Inductive
B. Capacitive
C. Parallel resonant circuit
D. Series resonant circuit
124. The quarter-wavelength transformer line acts as a transformer with a 1:1 turns ratio
when the load resistance is with what relationship with the characteristic impedance of
the quarter-wavelength transformer?
A. Equal
B. Less than
C. Greater than
D. None of these
A. 50 to 200
B. 25 to 50
C. 100 to 200
D. 50 to 75
126. The quarter-wavelength transformer line acts as a step down transformer when the load
resistance is with what relationship with the characteristic impedance of the quarter-
wavelength transformer?
A. Equal
B. Less than
C. Greater than
D. None of these
127. The typical value of the velocity factor of an open-wire transmission line is
A. 0.8
B. 0.7
C. 0.6
D. 0.9
128. If a transmission line is not terminated in its characteristic impedance, _______ will
develop along the line.
A. Traveling waves
B. Standing waves
C. Surge impedance
D. Infinite impedance
129. If a load and a line have mismatched impedances, power not absorbed by the load will
be _____.
A. Absorbed
B. Rejected
C. Reflected
D. Removed
MULTIPLE CHOICE QUESTIONS IN
INTRODUCTION TO
COMMUNICATIONS
Electronics Systems and Technologies
By
Melvin C. Arceo
ENCODED BY:
GARCIA, Virginia Nonna H.
1. It is the transmission, reception, and processing of information between two or more
locations using electronic circuits.
a. Electronic communications
b. Electronic transfer
c. Electronic mode
d. Electronic codes
4. Who was the first to successfully transmit wireless radio signals through Earths
atmosphere?
a. Samuel Morse
b. Howard Armstrong
c. Lee DeForest
d. Guglielmo Marconi
7. Calculate the noise power outputs of a 1 kilo ohm resistor at 27 degrees C over a 100-
kHz bandwidth.
a. 4.14 fW
b. 0.414 fW
c. 14.1 fW
d. 141 fW
8. _________ is a collection of electronic devices and circuits that accepts the transmitted
signals from the transmission medium and converts them back to their original form.
a. channel
b. receiver
c. transmitter
d. antenna
10. A signal that modulates a high-frequency signal or carrier in order to transfer information
from one location to another
a. intelligence
b. modulated signal
c. carrier
d. intelligence or modulated signal
11. Fourier series shows that a sawtooth wave consists of the following except
a. fundamental and subharmonic sine waves
b. a fundamental sine wave and an infinite number of harmonics
c. fundamental and harmonic sine waves whose amplitude decreases with the harmonic
number
d. sinusoidal voltages, some of which are small enough to ignore in practice
12. Determine the noise current for a diode with a forward bias of 1mA over a 1 MHz
bandwidth.
a. 19.8 nA
b. 17.9 nA
c. 12.3 nA
d. 15 nA
13. The process of changing one or more properties of the carrier in proportion with the
information signal?
a. demodulation
b. transmission
c. modulation
d. reception
14. A system where digital pulses are transferred between two points in a communication
system.
a. digital transmission
b. analog transmission
c. digital radio
d. analog communications system
15. It is the transmittal of digitally modulated analog carriers between two or more points in a
communication system.
a. analog transmission
b. digital radio
c. digital communications
d. digital reception
16. Type of modulation where the carrier amplitude is varied proportional to the information
signal.
a. AM
b. PM
c. FM
d. Pulse modulation
19. Calculate the signal to noise ratio for a receiver output of 4V signal and 0.48V noise in
dB
a. 18.5 dB
b. 69 dB
c. 25.4 dB
d. 9.25 dB
21. It performs the reverse process of modulation and converts the modulated carrier back to
the original information.
a. oscillator
b. demodulator
c. synthesizer
d. mixer
22. Indicate the false statement. The reasons why modulation is necessary in electronic
communications is because:
a. It is extremely difficult to radiate low-frequency signals from antenna in the form of
electromagnetic energy.
b. Information signals often occupy the same frequency band and, if signals from two or
more sources at the same time, they would interfere with each other.
c. To reduce the size of the capacitors and inductors of the tuned circuit.
d. To increase the size of the transmitting and receiving antenna.
23. The process of converting a frequency or band of frequencies to another location in the
total frequency spectrum is called:
a. translation
b. demodulation
c. modulation
d. oscillation
25. _________ is simply the number of times a periodic motion occurs in a given unit of time
a. frequency
b. time
c. period
d. phase
26. The difference between the highest and the lowest frequencies contained in the
information.
a. noise
b. bandwidth
c. interference
d. frequency
27. It is a highly theoretical study of the efficient use of bandwidth to propagate information
through electronic communications systems.
a. information capacity
b. information bandwidth
c. information theory
d. information entropy
28. It is the measure of how much information can be transferred through a communications
system in a given period of time.
a. information bandwidth
b. information capacity
c. information density
d. information theory
29. The law that states that the wider the bandwidth and the longer the time of transmission,
the more information that can be conveyed through the system.
a. Information theory
b. Information density law
c. Hartleys law
d. Information entropy law
30. A circuit configuration that involves one wire for the signal and one for the reference or
ground.
a. 2-wire
b. 4-wire
c. 3-wire
d. 1-wire
31. A circuit configuration that involves two for signal and two for reference or ground.
a. 2-wire
b. 4-wire
c. 3-wire
d. 1-wire
32. It is used to match impedances and provide isolation between the two directions of signal
flow.
a. 2-wire
b. hybrid set
c. 4-wire transmission
d. suppressors
33. An interface circuit that is used when a two-wire circuit is connected to a four-wire
circuit, as in long-distance telephone call.
a. suppressors
b. echo limiter
c. codec
d. terminating set
34. An amplifier with a noise figure of 6dB has an input signal-to-noise ratio of 25dB.
Calculate the output signal-to-noise ratio in dB.
a. 31 dB
b. 19 dB
c. 20 dB
d. 25 dB
35. It is the process of combining two or more signals and is an essential process in electronic
communications.
a. oscillation
b. mixing
c. damping
d. modulation
36. _________ occurs when two or more signals combine in a linear device, such as a
passive network or a small-signal amplifier.
a. non-linear mixing
b. linear-phase filtering
c. linear summing
d. bandlimiting
37. One of the following is not a useful quantity for comparing the noise performance of
receivers:
a. input noise voltage
b. equivalent noise resistance
c. noise temperature
d. noise figure
38. A single-stage amplifier has a 200-kHz bandwidth and a voltage gain of 100 at room
temperature. Assume that the external noise is negligible and that a 1-mV signal is
applied to the amplifiers input. Calculate the output noise voltage if the amplifier has a
5-dB NF and the input noise is generated by a 2-kilo ohm resistor.
a. 56.58 nV
b. 458 uV
c. 595.6 nV
d. 356 uV
39. In a communication system, which of the following reduces the information capacity of
the system.
a. linear-phase filtering
b. mixing
c. bandlimiting
d. modulation
40. _________ occurs when two or more signals are combined in a non-linear device such as
a diode or large-signal amplifier.
a. modulation
b. non-linear summing
c. oscillation
d. non-linear filtering
41. Measuring physical condition of some remote location and transmitting this data for
analysis is the process of
a. Telemetry
b. Instrumentation
c. Modulation
d. Multiplexing
42. It is defined as any undesirable electrical energy that falls within the passband of the
signal.
a. interference
b. noise
c. splatter
d. out-of-band signalling
43. _________ noise that is present regardless of whether there is a signal present or not.
a. atmospheric noise
b. correlated
c. uncorrelated
d. internal
44. A three stage amplifier has an input stage with noise ratio of 5 and power gain of 50.
Stages 2 and 3 have a noise ratio of 10 and power gain of 1000. Calculate the noise figure
for the overall system.
a. 4.55 dB
b. 7.14 dB
c. 6 dB
d. 5.18 dB
49. What is the noise whose source is in a category different from that of the other three.
a. solar noise
b. cosmic noise
c. atmospheric noise
d. galactic noise
50. A microwave antenna with an equivalent noise temperature of 25 K is coupled through a
network with an equivalent noise temperature of 30 K to a microwave receiver with an
equivalent noise temperature of 60 K referred to its input. Calculate the noise power at its
input for a 2-MHz bandwidth.
a. 3.15 fW
b. 4.35 fW
c. 2.12 fW
d. 1.24 fW
51. Which of the following is not another name of thermal agitation noise?
a. White noise
b. Pink noise
c. Johnson noise
d. Brown noise
52. Any modification to a stream of carriers as they pass from the input to the output of a
device produces an irregular, random variation is called _________ noise.
a. Transit-time noise
b. Man-made noise
c. Thermal noise
d. Internal noise
53. One of the following types of noise becomes of great importance at high frequencies. It is
the
a. shot noise
b. random noise
c. impulse noise
d. transit-time noise
54. The noise that was first observed in the anode current of a vacuum tube amplifier and was
described mathematically by W. Schottky in 1918.
a. Shot noise
b. Transit-time noise
c. External noise
d. Thermal agitation noise
57. _________ noise is noise that is mutually related to the signal and cannot be present in a
circuit unless there is an input signal input.
a. solar noise
b. uncorrelated noise
c. correlated noise
d. noise voltage
58. The square of the thermal noise voltage generated by a resistor is proportional to
a. its resistance
b. its temperature
c. Boltzmanns constant
d. The bandwidth over which it is measured
59. It is a type of distortion that when unwanted harmonics of a signal are produced through a
nonlinear amplification.
a. intermodulation distortion
b. buck-shot
c. splatter
d. harmonic distortion
65. _________ is a figure of merit used to indicate how much the signal-to-noise ratio
deteriorates as a signal passes through a circuit or series of circuits.
a. SINAD
b. Q-factor
c. Noise figure
d. S/N ratio
66. The value of resistor creating thermal noise is doubled. The noise power generated
therefore
a. halved
b. quadrupled
c. doubled
d. unchanged
70. It is where the electronic signal is sent from one place to another.
a. receiver
b. transmitter
c. source
d. channel
71. It is a broad general term applied to any form of wireless communication from one point
to another.
a. radio
b. frequency
c. signal
d. spectrum
72. Collection of electronic components and circuits that accept the transmitted message
from the channel and convert it back into a form understandable by humans.
a. receiver
b. medium
c. transmitter
d. converter
73. It is a random, undesirable, electric energy that enters a communications system via the
communicating medium and interferes with the transmitted message.
a. interference
b. noise
c. distortion
d. fluctuations
74. A system that transmits information about the physical status of the satellite including the
position and temperature.
a. telecommand
b. telemovement
c. television
d. telemetry
75. Regardless of whether information is analog or digital, these signals are referred to as
_________.
a. broadband
b. composite
c. baseband
d. any of these
76. Putting the original voice, video, or digital data directly into the medium is referred to as
_________.
a. baseband transmission
b. composite transmission
c. broadband transmission
d. data transmission
77. It is the process of having a baseband voice, video, or digital signal modify another,
higher-frequency signal.
a. mixing
b. summing
c. heterodyning
d. modulation
78. It is the process of transmitting two or more signals simultaneously over the same
channel.
a. modulation
b. multiplexing
c. summing
d. demodulation
87. Light is a special type of electromagnetic radiation which has a wavelength range of
a. 0.01 mm to 1000nm
b. 0.01 mm to 700 nm
c. 1000nm to 700 nm
d. 0.4 um to 0.8 um
90. It is the frequency range over which an information signal is transmitted or over which a
receiver or other electronic equipment operate.
a. composite
b. bandwidth
c. summed frequency
d. signals
93. Calculate the noise power at the input of a microwave receiver with an equivalent noise
temperature of 45 K. It is fed from an antenna with a 35 K equivalent noise temperature
and operates over a 5-MHz bandwidth.
a. 3.56 fW
b. 1.34 fW
c. 2.98 fW
d. 5.52 fW
94. It is the process of putting information onto a high-frequency carrier for transmission.
a. multiplexing
b. modulation
c. mixing
d. heterodyning
95. It is generally a device that converts energy from one form to another.
a. transformer
b. motor
c. transducer
d. generator
100. The process of converting a frequency or band of frequencies to another location in the
total frequency spectrum
a. modulation
b. detection
c. frequency translation
d. amplification
103. When the input power is reduced in half at the output, the signal power is said to be
reduced by:
a. 2 dB
b. 6 dB
c. 4 dB
d. 3 dB
104. A current change that is equal to twice its original value will correspond to a change of
a. 3 dB
b. 9 dB
c. 10 dB
d. 6 dB
105. There are four networks in series. The first network has a gain of 15 dB, the second has
a loss of 4 dB, the third gain of 35 dB, and the fourth a loss of 5 dB. The input of the
first network is +3dBm. What is the output to the last network in mW.
a. 15913.1
b. 19922.9
c. 25118.9
d. 29523.6
106. The PLL is often combined with _________ circuits to produce multiple frequencies.
a. Local oscillator
b. Mixer
c. RF amplifier
d. AF amplifier
110.It is a resistive network that is used to introduce a fixed amount of attenuation between
the source and a load.
a. limiter
b. clipper
c. mixer
d. attenuator
111.A technique used in improving communication when a high peak-to-average power ratio
of atmospheric noise occurs, the receiver is disabled during the duration of these burst.
a. quieting
b. noise blanking
c. limiting
d. mixing
112.It is the ratio of the signal power level to noise power level
a. noise figure
b. signal-to-noise ratio
c. SINAD
d. noise improvement factor
113.It is a figure of merit used to indicate how much the signal-to-noise ratio deteriorates as a
signal passes through a circuit or series of circuits.
a. Q-factor
b. signal-to-noise ratio
c. noise factor
d. numerical aperture
116.It is the relative measure of the desired signal power to the noise power
a. noise factor
b. signal-to-noise ratio
c. noise figure
d. noise improvement factor
118.It is the range of frequency in which the upper frequency is double the lower frequency
a. decade
b. pentade
c. octave
d. none of these
120. The formula used to measure the total noise figure due to amplifiers in cascade is called
_________.
a. Johnsons formula
b. Shannons formula
c. Hartleys formula
d. Friss formula
126. For a feedback circuit to sustain oscillation, the net voltage gain around the feedback
loop must be unity or greater, and the net phase shift around the loop must be positive
integer multiply of 360 degrees.
a. Barkhausen criterion
b. Butterworth criterion
c. Flywheel effect
d. Feedback criterion
127. A circuit which comprises of a voltage amplifier with an open-loop voltage gain, a
frequency-determining regenerative feedback path with a feedback ratio and either a
summer or subtractor circuit.
a. amplifier
b. closed-loop
c. power source
d. open-loop
128. It is the overall voltage gain of the complete circuit with the feedback loop closed and is
always less than the open-loop voltage gain.
a. feedback ratio
b. closed-loop voltage gain
c. open-loop current gain
d. close-loop current gain
130. It is an untuned RC shift oscillator that uses both positive and negative feedback.
a. LC tank circuit
b. Colpitts oscillators
c. Hartley oscillators
d. Wein-Bridge oscillators
131. Its operation involves an exchange of energy between kinetic and potential.
a. Wein-Bridge oscillators
b. LC tank circuit
c. Clapp oscillators
d. Hartley oscillators
133. It is a function of component aging and changes in the ambient temperature and
humidity.
a. short-term stability
b. damping
c. long-term stability
d. filtering
134. It is the study of the form, structure, properties and classifications of crystals
a. Crystallography
b. Stalactitomy
c. Crystallomagraphy
d. Stalagmitophy
135. It deals with lattices, bonding and behaviour of splices of crystal material that have been
cut at various angles with respect to the crystals axes.
a. Crystallography
b. Stalactitomy
c. Crystallomagraphy
d. Stalagmitophy
136. It occurs when oscillating mechanical stresses applied across a crystal lattice structure
generate electrical oscillations and vice-versa.
a. crystal effect
b. photoelectric effect
c. piezoelectric effect
d. solar effect
138. Which of the following crystals is often used for frequency control in oscillators?
a. EDT
b. Synthetic quartz
c. Tourmaline
d. Rochelle salt
140. It is a specially constructed diode whose internal capacitance is enhanced when reverse
biased, and by varying the reverse bias voltage, the capacitance of the diode can be
adjusted.
a. tunnel diode
b. SAW
c. backward diode
d. varactor
142. It is an oscillator circuit that generates well-defined, stable waveforms that can be
externally modulated or swept over a given frequency range.
a. swept generator
b. frequency synthesizer
c. wave generator
d. frequency synchronizer
144. It is defined as the range of frequencies in vicinity of the VCOs natural frequency over
which the PLL can maintain lock with an input signal.
a. capture range
b. lock range
c. bandwidth
d. free-running frequency
148. It is defined as the band of frequencies in the vicinity of the natural frequency where the
PLL can establish or acquire lock with an input signal.
a. tracking range
b. capture range
c. lock range
d. hold-in range
149. It is an oscillator with stable frequency of oscillation that depends on an external bias
voltage.
a. multiplier
b. monolithic controlled oscillator
c. voltage-controlled oscillator
d. phase-locked loop
152. It is used to generate many output frequencies through the addition, subtraction,
multiplication, and division of a smaller number of fixed frequency sources.
a. power amplifier
b. frequency synchronizer
c. oscillator
d. frequency synthesizer
153. A type of frequency synthesis in which multiple output frequencies are generated by
mixing the outputs from two or more crystal-controlled frequency sources or by
dividing
or multiplying the output frequency form a single-crystal oscillator.
a. direct frequency synthesis
b. constant frequency synthesis
c. indirect frequency synthesis
d. multiple frequency synthesis
154. It is the minimum frequency separation between output frequencies for the synthesizer.
a. dynamic range
b. resolution
c. octave
d. decade
158. The _________ gain for a PLL is simply the product of the individual gains or transfer
function for the loop.
a. loop
b. capture
c. lock
d. closed
160. What is the first symbol of a radio signal emission having amplitude modulated main
carrier?
a. C
b. B
c. H
d. A
161. The method of determining the bandwidth requirements for any processing system is
referred to as:
a. frequency spectrum
b. frequency analysis
c. spectral analysis
d. bandwidth analysis
163. Noise uniformly distributed over the voice frequency band is called _________ noise.
a. impulse
b. quantizing
c. intermodulation
d. white
164. In psophometric noise weighting, one picowatt is equivalent to 800 Hz tone with a
power of
a. -90 dBm
b. -85 dBm
c. -65 dBm
d. none of the above
167. At what power level does a 1 kHz tone causes zero interference (144 weighted)?
a. 90 dB
b. 90 dBm
c. -90 dB
d. -90 dBm
168. A tone of _________ Hz causes more interference than do other frequencies, in a voice
channel.
a. 300
b. 1000
c. 3400
d. 4000
169. A power of a standard test tone is normally _________.
a. 0 mW
b. 1 W
c. 1 dB
d. 1 mW
171. In an analog voice frequency channel, the unwanted change in phase or frequency
caused by modulation of another signal is;
a. Intrinsic noise
b. white noise
c. intermodulation
d. phase-jitter
173. What is the reference tone level for random noise measurement, F1A weighted?
a. -90 dBm
b. -82 dBm
c. -67 dBm
d. -85 dBm
175. If the transmitter output power of 10 watts is doubled, the gain derived is about:
a. 6 dB
b. 4 dB
c. 13 dB
d. noise of the above
176. When the power ratio of the input to output is 1/100, the loss of the circuit, in dB, is
a. 20
b. -20
c. -10
d. 3
177. An antenna which has a power gain of 30 dB would mean it could increase the output of
the transmitter by:
a. 10,000 times
b. 1,000 times
c. 100 times
d. 1 million times
179. The frequency band used by cellular telephones and cellular telephones and mobile
communication services is _________.
a. UHF
b. EHF
c. VHF
d. VLF
180. The radio wavelength known as _________ falls within the medium frequency range.
a. centimetric
b. decametric
c. hectometric
d. myriametric
183. Most impedance-matching networks are _________ filters, so they eliminate harmonics.
a. high-pass
b. low-pass
c. bandpass
d. bandstop
184. _________ are types of noise generated by equipments that produces sparks.
a. equipment noise
b. atmospheric noise
c. space noise
d. internal noise
185. A high-frequency noise occurs when the time taken by change carriers to cross a
junction is comparable to the period of the signal
a. pink noise
b. transit-time noise
c. white noise
d. flicker noise
186. The electromagnetic spectrum is managed worldwide by the _________ organization.
a. FCC
b. SI
c. ANSI
d. ITU
188. The bandwidth of a double-tuned transformer depends upon the degree of _________
between primary and secondary windings.
a. mutual inductance
b. coupling coefficient
c. limiting factor
d. filtering
191. The output frequency of a synthesizer is changed by varying the _________ of the
divider between the VCO and the phase detector.
a. Mixer output
b. IF output
c. Frequency division ratio
d. Voltage division ratio
192. The PLL is often combined with _________ circuits to produce multiple frequencies.
a. Local oscillator
b. Mixer
c. RF amplifier
d. AF amplifier
194. If a parallel LC circuit is at resonance, increasing C will cause the current to _________
the applied voltage.
a. lead
b. lag
c. lead-lag
d. lag-lead
195. Information sent in the form of coded dots and dashes is called _________ transmission.
a. baudot
b. continuous-wave
c. digital
d. any of these
197. Combining a feedback capacitor with the internal capacitance of the transistor forms a
_________ circuit which is used to cancel the self-oscillation.
a. filter
b. tank
c. bridge
d. feedback
198. Untuned RF transformers permit _________ operation over a wide frequency range.
a. narrowband
b. middleband
c. broadband
d. any of these
MULTIPLE CHOICE QUESTIONS IN
WAVE PROPAGATION
Electronics Systems and Technologies
By
Melvin C. Arceo
ENCODED BY:
GARCIA, Virginia Nonna H.
1. The cumulative sum of the direct, ground-reflected, and surface waves is reflected to as
_________.
a. Space wave
b. Ground wave
c. Sky wave
d. Direct waves
5. A range of microwave frequencies more easily passed by the atmosphere than the others
is called a
a. window
b. critical frequency
c. gyro frequency range
d. resonance in the atmosphere
6. It is simply the orientation of the electric field vector in respect to the surface of the Earth
a. Polarization
b. Wavefront
c. Rays
d. Power density
7. For an isotropic antenna radiating 100W of power, what is power density 1000m from the
source?
a. 1.99 uW/m^2
b. 7.96 uW/m^2
c. 3.22 uW/m^2
d. 9.17 uW/m^2
8. The ground wave eventually disappears, as moves away from the transmitter, because of
a. interference from the sky wave
b. loss of line-of-sight conditions
c. maximum single hop distance limitations
d. tilting
9. If the electric field is propagating parallel to the surface of the Earth, the polarization is
_________.
a. Circular
b. Vertical
c. Horizontal
d. Elliptical
10. A taxi company uses a central dispatcher, with an antenna at the top of a 15m tower, to
communicate with taxi cabs. The taxi antennas are on the roofs of the cars, approximately
1.5m above the ground. What is the maximum communication distance between the
dispatcher and a taxi?
a. 21 km
b. 30 km
c. 25 km
d. 33 km
11. The E layer of the ionosphere aid _________ propagation and reflects _________ waves
a. MF, HF
b. HF, MF
c. LF, MF
d. MF, LF
12. When microwave signals follows the curvature of the earth, it is known as
a. the Faraday effect
b. ducting
c. tropospheric scatter
d. ionospheric scatter
13. If the polarization vector rotates 360 degrees as the wave moves one wavelength through
space and field strength is equal at all angles of polarization, the polarization is
_________.
a. Vertically polarized
b. Horizontally polarized
c. Circularly polarized
d. Elliptically polarized
14. _________ travels essentially in a straight line between the transmit and the receive
antennas
a. Direct waves
b. Sky waves
c. Space waves
d. Surface waves
15. Variations brought about the revolution of the earth around the sun
a. weather variation
b. cyclical variation
c. diurnal variation
d. seasonal variation
16. The dielectric strength of air is about 3MV/m. Arching is likely to take place at field
strengths greater than that. What is the maximum power density of an electromagnetic
wave in air?
a. 40 GW/m^2
b. 15.5 GW/m^2
c. 23.9 GW/m^2
d. 18.9 GW/m^2
17. It is a single location from which rays propagate equally in all directions
a. point source
b. omnidirectional source
c. ideal polarization
d. isotropic polarized
20. The rate at which energy passes through a given surface area in free space is called
_________.
a. capture power
b. capture area
c. captured power density
d. power density
21. A radio wave moves from air (relative permittivity is 1) to glass (relative permittivity is
7.8). Its angle of incidence is 30 degrees. What is the angle of refraction?
a. 10.3 degrees
b. 11.2 degrees
c. 20.4 degrees
d. 0.179 degrees
22. It is the intensity of the electric and the magnetic fields of the electromagnetic wave
propagating in free space
a. field intensity
b. field density
c. power intensity
d. power intensity
26. The transmitting distance with direct waves is limited to short distances and strictly a
function of the _________ of the transmitting and receiving antenna.
a. frequency
b. phase
c. power
d. height
28. It is the deflection or bending of electromagnetic waves such as radio waves, light or
even sound when the waves cross the boundary line between two mediums with different
characteristics.
a. reflection
b. diffraction
c. refraction
d. dispersion
29. The reduction of power density with distance is equivalent to a power loss.
a. absorption
b. attenuation
c. distance loss
d. power dissipation
30. The signal refracted back from the ionosphere strikes the earth and is reflected back up to
the ionosphere again to be bent and sent back to earth.
a. skip transmission
b. multi-hop transmission
c. multi transmission
d. hop transmission
33. _________ is the signal that is radiated by the antenna into the atmosphere where it is
bent or reflected back to earth.
a. ground wave signal
b. sky wave signal
c. space wave signal
d. direct waves signal
35. It is defined as the modulation or redistribution of energy within a wave front as it passes
near the edge of an opaque object.
a. refraction
b. scattering
c. reflection
d. diffraction
37. It states that every point on a given spherical wavefront can be considered as a secondary
point source of electromagnetic waves from which other secondary waves or wavelets are
radiated outward.
a. Hertzian principle
b. Maxwells principle
c. Huygens principle
d. Marconis principle
38. Calculate the electric field intensity, in volts per meter, 20 km from a 1-kW source.
a. 3.44 mW/m
b. 7.65 mW/m
c. 8.66 mW/m
d. 1.45 mW/m
40. Calculate the radio horizon for a 500-ft transmitting antenna and receiving antenna of 20
ft.
a. 23.1 mi
b. 31.2 mi
c. 14.8 mi
d. 37.9 mi
41. Calculate the power received from a 20-W transmitter, 22,000 miles from earth, if the
receiving antenna has an effective area of 1600m^2
a. 4.06 x 10^-12 W
b. 2.03 x 10^-12 W
c. 1.02 x 10^-12 W
d. 0.91 x 10^-12 W
42. As electromagnetic waves travel in free space, only one of the following can happen to
them
a. absorption
b. attenuation
c. refraction
d. reflection
43. Electromagnetic waves travelling within Earths atmosphere is called
a. Space wave
b. Surface wave
c. Terrestrial wave
d. Sky-wave
44. Calculate the power density in watts per square meter (on earth) from a 10-W satellite
source that is 22,000 miles from earth.
a. 3.17 x 10^ -16 W/m^2
b. 6.35 x 10^ -16 W/m^2
c. 2.31 x 10^ -16 W/m^2
d. 1.21 x 10^ -16 W/m^2
45. It is termed used to describe variations in signal strength that occur at the receiver during
this time a signal is being received.
a. skipping
b. attenuation
c. absorption
d. fading
47. It is the tendency of the sun to have grayish-black blemishes, seemingly at random times
and at random place, on its fiery surface.
a. solar intensity
b. sunspot
c. solar flare
d. solar flux
49. It is an earth-guided electromagnetic wave that travels over the surface of the Earth
a. Surface waves
b. Sky waves
c. Direct waves
d. Space waves
51. The curvature of the Earth presents a horizon to space wave propagation commonly
called _________.
a. Optical horizon
b. Radio horizon
c. Horizontal horizon
d. Vertical horizon
52. Electromagnetic waves that are directed above the horizon level is called _________.
a. direct waves
b. sky waves
c. space waves
d. surface waves
53. The refracting and reflecting action of the ionosphere and the ground is called
a. sliding
b. skipping
c. hopping
d. boosting
55. The layer of the ionosphere which farthest from the sun
a. D layer
b. E layer
c. F1 layer
d. F2 layer
59. It is defined as the higher frequency that can be propagated directly upward and still be
returned to earth by the ionosphere
a. critical angle
b. maximum usable frequency
c. critical frequency
d. virtual height
60. The maximum vertical angle at which electromagnetic waves can be propagated and still
be reflected back by the ionosphere
a. numerical aperture
b. incident angle
c. critical angle
d. refracted angle
62. It is the height above Earths surface from which a reflected wave appears to have been
reflected.
a. virtual height
b. maximum height
c. vertical height
d. horizontal height
63. It is the highest frequency that can be used for sky wave propagation between two
specific points on Earths surface
a. optimum working frequency
b. maximum usable frequency
c. critical frequency
d. maximum frequency
64. The polarization of electromagnetic waves can be determined by the direction of the
a. E field
b. H field
c. propagation
d. both E and H field
66. It is defined as the minimum distance from the transmit antenna that a sky wave at a
given frequency will be returned to earth.
a. skip distance
b. skip zone
c. skip frequency distance
d. skip zone frequency
67. At distance greater than the skip distance, two rays can take different paths and still be
returned to the same point on Earth. The two rays are called lower rays and _________.
a. Pedersen ray
b. Light ray
c. Huygens ray
d. Millers ray
69. The area between where the surface waves are completely dissipated and the point where
the first sky wave returns to earth is called _________.
a. skip distance
b. skip distance zone
c. optical horizon
d. quiet zone
70. The undesired radiated energy that may cause interference with other electronic
equipment in the vicinity.
a. ESD
b. EMI
c. RFI
d. ESI
72. To increase the transmission distance of a UHF signal, which of the following should be
done?
a. increase the antenna gain
b. increase antenna height
c. increase transmitter power
d. increase receiver sensitivity
73. For a carrier frequency of 6 GHz and a distance of 50 km, determine the free-space path
loss
a. 132 dB
b. 123 dB
c. 142 dB
d. 152 dB
74. A microwave-transmitting antenna is 550 ft high. The receiving antenna is 200 ft high.
The maximum transmission distance is
a. 20 mi
b. 33.2 mi
c. 38.7 mi
d. 53.2 mi
75. Indicate which one of the following term applies to troposcatter propagation
a. SIDs
b. Fading
c. Atmospheric storms
d. Faradays rotation
77. VLF waves are used for some types of services because
a. of the low powers required
b. the transmitting antenna are of convenient size
c. they are very reliable
d. affected by the solar cycle
79. Indicate which of the following frequencies cannot be used for reliable beyond-the-
horizon terrestrial communications without repeaters:
a. 20 kHz
b. 15 MHz
c. 900 MHz
d. 12 GHz
80. The type of radio wave responsible for long-distance communications by multiple skips
is the
a. ground wave
b. direct wave
c. surface waves
d. sky wave
82. The ionosphere has its greatest effect on signals in what frequency range?
a. 300 kHz to 3 MHz
b. 3 to 30 MHz
c. 30 to 300 MHz
d. above 300 MHz
83. Distances near the skip distance should be used for sky-wave propagation
a. to avoid tilting
b. to prevent sky-wave and upper ray interference
c. to avoid Faraday effect
d. so as not to exceed the critical frequency
86. Helical antenna are often used for satellite tracking at VHF because of
a. troposcatter
b. superrefraction
c. ionospheric refraction
d. the Faraday effect
87. A ship-to-ship communication system is plagued by fading. The best solution seem to use
of
a. a more directional antenna
b. a broadband antenna
c. frequency diversity
d. space diversity
88. It is defined as the ratio of the electric field intensity of the reflected wave to that of the
incident wave
a. refractive index
b. numerical aperture
c. reflection coefficient
d. absorption coefficient
89. It is the measure of energy received per unit time, per unit area, per unit frequency
interval.
a. solar intensity
b. sunspot
c. solar flare
d. solar flux
91. As a ground-wave signal moves away from the transmitter, the ground wave eventually
disappears due to the
a. absorption
b. tilting
c. refraction
d. diffraction
92. It is the lowest layer of the atmosphere where all weather disturbances takes place
a. D layer
b. Stratosphere
c. Ionosphere
d. Troposphere
93. It is the lower limit of the range of frequencies that provide useful communication
between two given points by the way of the ionosphere.
a. MUF
b. LUF
c. OWF
d. MMF
94. It is the area that lies between the outer limit of the ground-wave range and the inner edge
of energy return from the ionosphere
a. skip distance
b. skip zone
c. virtual height
d. optical horizon
95. Variations brought about by the rotation of the earth around its axis.
a. cyclical rotation
b. seasonal variation
c. diurnal variation
d. weather variation
96. Ionospheric irregularity caused by solar flares, which are gigantic emissions of hydrogen
from the sun.
a. Sudden ionospheric disturbances
b. Dillenger fadeouts
c. Mogul-Delliger fadeouts
d. Any of these
99. An increase in temperature with height which gives rise to superrefraction or ducting is
known as _________.
a. height inversion
b. depth inversion
c. temperature inversion
d. ionospheric inversion
100. A region in which superrefraction occurs which is formed in the troposphere when the
layer of cool air becomes trapped underneath a layer of warmer air.
a. duct
b. dielectric area
c. gateway
d. window
103. It is a device that permits two different transmitters to operate with a single antenna
a. duplexer
b. diplexer
c. isolator
d. circulator
105. A diversity scheme wherein the receiver receives two fading signals from two different
directions
a.frequency diversity
b. time diversity
c.angle diversity
d. space diversity
106. The radio wavelength known as _________ falls within the medium frequency range
a. centimetric wave
b. decametric wave
c. hectometric wave
d. myriametric wave
108. The frequency band used as sub-carriers, or signals which carry the baseband
modulating information but in turn modulate another higher-frequency carrier is
_________.
a. LF
b. MF
c. VLF
d. VH
109. The range of frequency band termed as super high frequency (SHF) is within
_________.
a. 30-300 GHz
b. 30-300 MHz
c. 3-30 GHz
d. 300-3000 MHz
110. Electric field that lies in a plane perpendicular to the earths surface.
a. circular polarization
b. vertical polarization
c. horizontal polarization
d. elliptical polarization
111. The magnetic field of an antenna is perpendicular to the earth. The antennas
polarization
a. is vertical
b. is horizontal
c. is circular
d. cannot be determined from the information given
112. The surface wave is effective only at frequencies below about _________ MHz.
a. 30
b. 3
c. 300
d. 0.3
115. What wavelength radiations tend to be transmitted entirely between ionosphere and
earth?
a. long
b. short
c. medium
d. millimeter
By
Melvin C. Arceo
ENCODED BY:
GIRAO, Edward Joseph D.
1. It is defined as knowledge or intelligence that is communicated between two or more points.
A. Carrier
B. Sideband
C. Information
D. Broadband
2. What is the category of data transmission if the binary pulse is maintained for the entire bit
time?
A. Return to zero
B. Bipolar
C. Unipolar
A. Twin lead
B. Fiber-optic cable
C. Twisted pair
D. Coax
4. These are used for transmission of PCM encoded time-division multiplexed digital signal
A. I carriers
B. E carriers
C. A carriers
D. T carriers
A. telemetry
B. stereo broadcasting
C. telephone
D. secure communications
6. A LAN device that use to interconnect two networks that use different protocols and formats
A. Gateways
B. Routers
C. Bridges
D. Hubs
7. A pulse modulation technique as the width of a constant amplitude pulse is varied proportional
to the amplitude of the analog signal at the time the signal is sampled.
9. It is the transmittal of digitally modulated analog signals (carrier) between two or more points
in a communications system.
A. Digital Modulation
B. Digital Transmission
C. Digital Communications
D. Pulse Modulation
A. Pulse-position modulation
B. Pulse-code modulation
C. Pulse-width modulation
D. Pulse-frequency modulation
11. Classification of protocol that interprets a frame of data as a group of successive bit
combined into predetermined pattern of fixed length, usually 8 bits each.
A. Character-oriented protocols
B. Byte-oriented protocols
C. Bit-oriented protocol
12. Dividing the data block by a constant produces a remainder that is used for error detection. It
is called the
A. Jam-proof
B. Security
C. Immunity to fading
D. Noise proof
A. quantizing
B. companding
C. pre-emphasis
D. mixing
A. Sampling
B. Coding
C. Quantization
D. Aliasing
A. Slot time
B. Transmission time
C. Frame time
D. Bit rate
B. Composite baseband
C. Information
D. Composite carrier
A. equipment failures
B. typing mistakes
C. noise
A. QAM
B. ASK
C. PSK
D. FSK
A. Mark, space
B. Space, mark
C. Space, space
D. Mark, mark
22. It is the processing of analog signals using digital methods and includes bandlimiting and
signals with filters, amplitude equalization, and phase shifting
A. Digital communications
C. Data communications
23. It is a network access method used primarily with LANs configured in a ring topology using
either baseband or broadband transmission formats.
A. Ethernet
B. Token passing
C. Token ring
D. Token bus
24. A small telephone switching system that can be used as a LAN is called
A. Ring
B. WAN
C. UART
D. PBX
25. The most common method used for sampling voice signals in PCM systems.
A. unnatural sampling
C. natural sampling
D. free sampling
A. Analog-to-digital Converter
B. Digital-to-analog Converter
C. Pre-emphasis circuit
D. Compander
27. The OSI layer that provides the control functions necessary to establish manage, and
terminate the connections as required to satisfy the user request.
A. Application layer
B. Network layer
C. Session layer
D. Physical layer
A. digital transmission
B. digital sampling
C. digital radio
D. data transmission
A. Coding efficiency
B. Companding
C. Pre-emphasis
D. Dynamic Range
32. Type of PCM which is designed to take advantage of the sample-to sample redundancies in
the typical speech waveform
C. Differential PCM
D. Data modulation
33. The Basic Rate Interference (BRI) of ISDN has a total bit rate of ______
A. 192 kbps
B. 148 kbps
C. 64 kbps
D. 1.544 Mbps
A. ASK
B. PSK
C. FSK
D. QAM
A. XOR
B. Multiplexer
C. Shift register
D. Mixer
B. Bandpass filter
C. Discriminator
D. Subcarrier oscillator
37. _____ defines how a user gets control of the channel so as to allow transmission.
A. channel access
B. collision detection
C. collision avoidance
D. carrier sense
A. ring
B. bus
C. star
D. square
A. probability of errors
B. error detection
C. error control
40. It is simply the data rate at which serial PCM bits are clocked out of the PCM encoder onto
the transmission line.
A. line speed
B. baud rate
C. output rate
D. bit rate
41. A quantizing is _____
A. Multiplexer
B. Demultiplexer
C. A/D converter
D. D/A converter
42. Refers to the rate of change of a signal on a transmission medium after encoding and
modulation have occurred
A. baud rate
B. phase shift
C. bit rate
D. frequency deviation
43. The magnitude difference between adjacent steps in quantization is called _____
A. Quantum
B. Step size
C. Resolution
D. Any of these
44. It is a set of rules implementing and governing an orderly exchange of data between layers
of two devices, such as line control units and front-end processors.
B. Network Protocol
45. A signaling system in which each letter of the alphabet is represented by a different symbol is
not used because
B. it is redundant
C. noise would introduce too many errors
46. A modulation process that involves conversion of a waveform from analog to digital form by
means of coding
A. PDM
B. PCM
C. PLM
D. PAM
47. What is the bandwidth required to transmit at a rate of 10 Mbps in the presence of a 28-Db
S/N ratio?
A. 1.075 MHz
B. 10 MHz
C. 5 MHz
D. 10.75 MHz
48. The slope of the analog signal is greater than the delta modulator can maintain
A. overload distortion
B. granular noise
C. slope overload
D. peak limiting
49. A scheme in which several channels are interleaved and then transmitted together is known as
B. time-division multiplex
C. a group
D. a supergroup
A. PLL discriminator
B. Pulse-averaging discriminator
C. Foster-Seeley discriminator
D. Ratio detector
51. What property distinguishes digital radio systems from conventional analog communications
system?
A. See-through
B. Transparent
C. Vague
D. Opaque
A. FSK
B. BPSK
C. DPSK
D. QAM
A. Antipodal signaling
B. Carrier recovery
C. Squaring loop
D. Phase referencing
A. Subcarrier
B. Bandpass filters
C. A/D Converters
D. FET switches
57. It is the ratio of the transmission bit rate to the minimum bandwidth required for a particular
modulation scheme.
A. Bandwidth efficiency
B. All of these
C. Information density
D. Spectral efficiency
59. It is a system where the digital signals are placed directly on the coaxial cable.
A. Broadband
B. Baseband
C. CSMA/CD
D. Token ring
A. telephone
B. teletype
C. telegraph
D. CW
62. Packets which is self-contained and travels through the network independent of other packets
of the same message by whatever means available.
A. Packet
B. Frame
C. Datagram
D. Data
63. Transmitting the data signal directly over the medium is referred to as
A. baseband
B. broadband
C. ring
D. bus
64. The main reason that serial transmission is preferred to parallel transmission is that?
A. serial is faster
B. serial requires only a single channel
A. PBX system
B. Hospital system
D. Cable TV system
66. A modulation technique where data rates in excess of 56 kbps can be achieved over telephone
circuits
A. ASK
C. GSK
D. any of these
67. It is how the primary designates the secondary as a designation or recipient of data.
A. Line turnaround
B. Selection
C. Line control
D. Control protocol
68. It is the process of compressing and expanding and is a means of improving the dynamic
range of a communications system.
A. Pre-emphasis
B. Filtering
C. De-emphasis
D. Companding
D. fed in at a GTE
70. The time it takes to transmit one TDM frame is called _____
A. Slot time
B. Frame time
C. Transmission time
D. any of these
B. thermal noise
72. It is the procedure used to decide which device has the permission to transmit at any given
time.
A. Flow control
B. Sequence control
C. Line control
D. Frame
73. Any rounded-off errors in the transmitted signal are reproduced when the code is converted
back to analog in the receiver
A. Aperture error
B. Quantization error
C. Aperture distortion
D. Slope overload
74. The biggest disadvantage of PCM is
A. Transmission one
B. Telecommunication one
C. Telex one
76. Involves compression in the transmitter after the input pulse has been converted to a linear
PCM code and then expansion in the receiver prior to PCM coding
A. analog companding
B. A-law companding
C. digital companding
D. u-law companding
D. on and off
78. Variation of biphase that is used for encoding SMPTE (Society of Motion Picture and
Television Engineers) time code data and for recording on video tapes
A. Biphase-M
B. B8Z
C. Manchester
D. UPNRZ
80. The ISDN channel D designates _____ which contains control information.
A. Data
B. Flow
C. Control
D. Bearer
81. A transmission of binary data which involves the transmission of two non-zero voltage level
A. Unipolar
B. Polar
C. Bipolar
D. Nonreturn to Zero
83. It involves converting standard logic levels to a form more suitable to telephone transmission
lines
D. Multiplexing
A. economical
B. reliability
C. noise immunity
D. efficiency
85. Part of the PCM system that prevents aliasing or foldover distortion
A. Bandpass filter
B. Anti-foldover distortion
C. Anti-aliasing
D. Any of these
86. It is defined as the process of transforming messages or signals in accordance with a definite
set of rules.
A. Quantizing
B. Sampling
C. Coding
D. Decoding
87. The PCM code for each channel occupies a fixed time slot called
A. Frame time
B. Baud
C. Transmission line
D. Epoch
A. Shift register
B. XOR
D. UART
89. An IC that contains A/D and D/A converters, companders, and parallel-to-serial converters is
called a
A. Codec
B. Data converter
C. Multiplexer
D. Modem
A. voice
B. video
C. computer data
D. all of above
91. The number of amplitude, frequency, or phase changes that take place per second is known as
the
B. frequency of operation
C. speed limit
D. baud rate
A. PLLs
B. Balanced modulators
C. Shift registers
D. Linear summers
93. What is the result if the input of ADC is changing while performing vonersion?
A. Aperture error
B. Overload distortion
C. Aliasing
D. Aperture distortion
A. baud
B. bits
C. dot length
A. twin lead
B. fiber-optic cable
C. twisted pair
D. coax
A. Bearer
B. Data
C. Control
D. Flow
98. Data transmission of the character at a time with start and stop bits is known as what type of
transmission?
A. asynchronous
B. serial
C. synchronous
D. parallel
99. Sampling technique that when the tops of the sample pulses retain their natural shape during
the sample interval
A. unnatural sampling
C. natural sampling
D. free sampling
D. none of these
101. It is a large scale integration chip designed for use in telecommunication industry for private
branch exchanges, central office switches, digital handsets and digital echo suppressors.
A. Vocoder
B. Modem
C. Codec
D. Muldem
102. What is the type of mastergroup used for low-capacity microwave systems?
A. A600
B. U600
C. L600
D. L400
A. Supergroup
B. Group
C. Mastergroup
D. Jumbogroup
104. The result whenever the sampling rate is less than the twice the highest audio frequency
A. peak limiting
B. overload distortion
C. alias
D. quantizing noise
105. The most critical and difficult part of receiving a direct-sequence spread spectrum is
A. Frequency synthesis
B. Synchronism
D. Carrier recovery
A. Supergroup
B. Group
C. Mastergroup
D. Jumbogroup
107. It is the transmittal of digital signals between two or more points in a communications
system.
A. digital transmittal
B. digitals communications
C. digital radio
D. data communications
108. It is logically equivalent to making telephone call through the DDD network except no
direct end-to-end connection is made
A. Normal call
B. Completed call
C. Logical call
D. Virtual call
109. It is a proposed network designed by major telephone companies in conjunction with the
ITU-T with the intent of providing worldwide telecommunications support for voice, data, video,
and facsimile information within the same network.
A. ISDN
B. Broadband communications
C. ATM
D. Ethernet
D. all of these
A. Morse
B. ASCII
C. Baudot
D. EBCDIC
112. Ten bit errors in two million transmitted. The bit error rate is
5
A. 2 10
5
B. 5 10
6
C. 5 10
6
D. 2 10
113. It is a type of FSK where the mark and space frequencies are synchronized with the input
binary rate
A. QFSK
B. GFSK
C. CPFSK
D. GSK
114. A form of digital modulation similar to PSK except the digital information is contained in
both the amplitude and the phase of the transmitted carrier.
A. ASK
B. FSK
C. QAM
D. PSK
115. For a 16-PSK and a transmission system with a 10 kHz bandwidth, determine the maximum
bit rate
A. 40,000 bps
B. 80,000 bps
C. 20,000 bps
D. 16,000 bps
116. It is an empirical record of a systems actual bit error performance.
A. probability of error
B. error detection
C. error control
117. It is a function of the carrier-to-noise power ration and the number of possible encoding
conditions used
A. probability of error
B. error detection
C. error control
118. It is used to compare two or more digital modulation systems that use different transmission
rates, modulation scheme or encoding techniques
D. carrier-to-noise ratio
A. Morse
B. Baudot
C. CCITT-2
D. ARQ
120. To permit the selection of 1 out of 16 equiprobable events, the number of bits required is
A. 2
B. log 16 base 10
C. 8
D. 4
121. The type of modulation most often used with direct-sequence spread spectrum is
A. QAM
B. SSB
C. FSK
D. PSK
123. Which of the following is not commonly used method of error detection?
A. Parity
B. BCC
C. CRC
D. redundancy
A. time-division multiplex
B. frequency-division multiplex
C. pulse-code modulation
A. digital communications
B. quantizing
C. PAM
D. PCM
A. quantizing
B. companding
C. pre-emphasis
D. sampling
129. Which circuit is common to both frequency-hopping and direct-sequence spread spectrum
transmitters?
A. Correlator
B. Frequency synthesizer
D. Sweep generator
130. One of the most important aspect of any communication system because its costly and
limited
A. bandwidth
B. equipments
C. time
D. personnel
131. It consist essentially of sampling analog information signals and then converting those
samples into discreet pulses of transporting the pulses from a source to destination over a
physical transmission medium
A. pulse modulation
B. amplitude modulation
C. frequency modulation
D. digital modulation
A. N.S. Kapany
B. A.H. Reeves
C. E.H. Alpine
A. analog methods
B. digital methods
C. either of these
D. neither of these
134. An integrated circuit that performs the PCM encoding and decoding functions
A. Codec
B. Modem
C. Muldem
D. Digital-to-analog converter
A. SYN
B. STX
C. SOH
D. ETB
136. A theorem that establishes the minimum sampling rate that can be used for a given PCM
systems
D. Any of these
137. Sixteen different levels (symbols) are used to encode binary data. The channel bandwidth is
36 MHz. the maximum channel capacity is
A. 187 Mbps
B. 72 Mbps
C. 288 Mbps
D. 2.176 Gbps
A. Coding
B. Quantizing
C. Sampling
D. Any of these
A. Parity
B. Xmodem
C. CRC
D. LRC
140. It is the ratio of the largest possible magnitude to the smallest possible magnitude that can
be decoded by the digital-to-analog converter in the receiver
A. Coding efficiency
B. Companding
C. Pre-emphasis
D. Dynamic range
A. codec
B. muldem
C. vocoders
D. modem
142. What is the minimum bandwidth required to transmit 56 kbps binary signal with no noise?
A. 14 kHz
B. 56 kHz
C. 28 kHz
D. 112 kHz
143. Type of PCM that uses single-bit PCM code to achieve digital transmission of analog
signals
C. Differential modulation
D. Delta modulation
144. It is a delta modulation system where the step size of the Digital-to-Analog converter is
automatically varied, depending on the analog input signal
D. Delta modulation
A. XNOR
B. Bit splitter
C. Balanced modulator
146. It is a form of phase-division multiplexing where two data channels modulate the same
carrier frequency that is shifted 90 degrees in phase.
A. PSK
B. FSK
C. QAM
D. ASK
A. FDM frame
C. TDM frame
148. It is a communication system that uses digital pulse rather than analog signals to encode
information
149. A special device that upgrades signals from one level to a higher level of the hierarchy in
multiplexing
A. Muldem
B. Vocoder
C. Modem
D. Codec
150. A transmission of binary data which involves the transmission of only a single non-zero
voltage level.
A. Unipolar
B. Polar
C. Bipolar
D. Nonreturn to zero
151. If the active time of the binary pulse is less than 100% of the bit time
B. Bipolar
C. Unipolar
D. Return to zero
152. It is a popular type of line encoding that produces a strong timing component for clock
recovery and does not cause wandering
A. Digital biphase
B. diphase
C. Manchester code
D. Any of these
A. Intelligent TDMs
B. Asynchronous TDM
C. Stat mux
D. Any of these
154. A chip that combines the codec and filter functions in the same LSI chip
A. Monolithic
B. Combo chip
C. Film IC
D. Hybrid chip
A. Character channel
B. Broadband channel
C. Message channel
D. Information capacity
156. It is the next higher level in the FDM hierarchy above the basic message channel and
consequently is the first multiplexing step for combining message channels
A. Supergroup
B. Group
C. Mastergroup
D. Jumbogroup
A. Broadband
B. Baseband
C. Carrier
D. Any of these
158. What type of mastergroup that can be further multiplexed and used for higher-capacity
microwave radio systems?
A. A600
B. U600
C. L600
D. L400
159. It is essentially the same with FDM, where several signals are transmitted using different
carriers, occupying non-overlapping bands of frequency and wavelengths.
A. AND gates
B. bandpass filters
C. differentiation
D. integration
A. AND gates
B. bandpass filters
C. differentiation
D. integration
A. reactance modulator
B. varactor
C. VCO
D. PLL
A. twin lead
B. twisted pair
C. fiber-optic cable
D. coax
165. A mainframe computer connected to multiple terminals and PCs usually uses which
configuration?
A. bus
B. ring
C. star
D. tree
A. 300
B. 900
C. 3600
D. 10800
167. In a PAM/TDM system, keeping the multiplexer and DEMUX channels step with one
another is done by a
B. sync pulse
C. sampling
D. sequencer
168. It is the process of volume compression before transmission and expansion after detection.
A. pre-emphasis
B. de-emphasis
C. coding
D. companding
170. Function of data link protocol that coordinates the rate at which data are transported over a
link and generally provides an acknowledgement mechanism that ensures that data are received
in the destination.
A. Flow control
B. Line discipline
C. Polling
D. Selection
A. Message oriented
B. Bit-oriented protocol
D. Asynchronous protocol
172. A LAN device that interconnects two or more device running identical internetwork
protocols.
A. Bridges
B. Gateways
C. Switches
D. Routers
173. The magnitude of a quantum in quantization of PCM codes.
B. Dynamic range
C. Resolution
D. Coding level
A. Message channel
B. Radio channel
C. Baseband channel
D. Wide channel
A. SONET
B. Frame relay
C. ATM
D. X.25
C. using u-law
D. forming supermastergroups
177. Results when the sample exceeds the highest quantization interval
A. Overload distortion
B. Quantization error
C. Quantization noise
D. Granular noise
178. The event which marked the start of the modern computer age was
A. Generated by an oscillator
D. all of these
183. In digital modulation, if the information signal is digital and the amplitude of the carrier is
varied proportional to the information signal.
A. FSK
B. BPSK
C. QPSK
D. QAM
A. 10 Mbps
B. 1.544 Mbps
C. 2.048 Mbps
D. 11 Mbps
186. Type of analog companding used in the United States and Japan
A. log-PCM companding
B. A-law companding
C. u-law companding
D. any of these
A. handshake
B. error-detection
C. data specifications
D. protocol
B. parity bit
C. CRC
D. error correction
190. What is the relationship of bit rate and baud in QPSK and 8-PSK?
A. Trellis code
B. Bandwidth efficiency
C. Squaring loop
D. Carrier recovery
192. What is the relationship of bit rate and baud in FSK and PSK?
A. greater than
D. equal
A. AM
B. FM
C. SSB
D. PSK
194. In digital modulation, a diagram which is similar to phasor diagram except that the entire
phasor is not drawn and only the peaks of the phasor are shown
A. constellation diagram
B. Venn diagram
C. phasor diagram
D. schematic diagram
A. AM
B. FM
C. SSB
D. PSK
198. It is highly theoretical study of efficient use of bandwidth to propagate information through
electronic communications system
A. information capacity
B. data communications
C. information theory
D. information technology
200. It is the process of gathering data on some particular phenomenon without the presesnce of
human monitors
A. Telemetry
B. Telecommand
C. Telecommunications
D. Remote control
201. A convenient technique for determining the effects of the degradations introduced into the
pulses as they travel to the regenerator.
B. Eye patterns
C. Reflection coefficient
D. Any of these
202. Spread spectrum stations sharing a band are identified by and distinguished from one
another
A. PSN code
B. Frequency of operation
C. Clock rate
D. Modulation type
A. 4 bits
B. 5 bits
C. 7 bits
D. 8 bits
204. The first file transfer protocol designed to facilitate transferring data between two personal
computers over the public switched telephone network
A. X modem protocol
B. Y modem protocol
C. Z modem protocol
D. BLAST
205. For a single-channel PCM system with a sample rate of 6000 samples per second and a
seven-bit compressed PCM code, what is the line speed?
A. 21,000 bps
B. 42,000 bps
C. 14,000 bps
D. 12,000 bps
206. It is often used to compare the performance of one digital modulation technique to another
A. Bandwidth efficiency
B. Spectral efficiency
C. Information density
D. All of these
207. It is the process of extracting a phase-coherent reference carrier from a receiver signal
A. Phase referencing
B. Trellis code
C. Squaring loop
D. any of these
208. It is the measure of how much information can be propagated through a communication
system and is a function of a bandwidth of the transmission line
A. information theory
B. information capacity
C. information technology
D. digital communications
A. continuous ADC
B. tracking ADC
D. slope ADC
A. Baudot
B. ASCII
C. CCITT-2
D. EBCDIC
211. Form of multiplexing that constitutes propagating signals from different cables that sre
contained within the same trench
212. For an 8-PSK system, operating with an information bit rate of 24 kbps, determine the
bandwidth efficiency
A. 8 bits/cycle
B. 2 bits/cycle
C. 3 bits/cycle
D. 4 bits/cycle
213. Element of a PCM system that periodically samples the analog input signal and converts
those samples to a multilevel PAM signal
A. Bandpass filter
B. Sample-and-hold circuit
C. Analog-to-digital converter
D. Digital-to-analog converter
214. It is the ratio of the average carrier power to the thermal noise power
A. Signal-to-noise ratio
B. Noise figure
C. Noise factor
D. Carrier-to-noise ratio
A. Packet switching
B. Message switching
C. Circuit switching
D. Digital switching
B. Companding
C. Coding efficiency
D. Dynamic range
217. Type of multiplexing where multiple sources that originally occupied the same frequency
spectrum are each converted to a different frequency band and transmitted simultaneously over a
single transmission medium.
A. FDM
B. ATM
C. TDM
D. Spread spectrum
218. It is a solicitation sent from the primary to a secondary to determine if the secondary has
data to transmit
A. Selection
B. Polling
C. Error control
D. Master control
219. Function of data link control that specifies the means of detecting and correcting
transmission errors
A. Error control
B. Selection
C. Protocol
D. Synchronization
221. It represents the number of independent symbols that can be carried through a system in a
given unit of time.
A. information theory
B. information capacity
C. information technology
D. digital communications
A. refers to distortion
D. refers to noise
A. bit
B. baud
D. any of these
224. Function of data link protocol that coordinates hop-to-hop data delivery where a hop maybe
a computer, a network controller or a network-connecting device such as router.
A. Flow control
B. Error control
C. Line discipline
D. Selection
C. AM plus QPSK
D. AM plus FSK
A. frequency-shift keying
B. two-tone modulation
C. pulse-code modulation
D. single-tone modulation
227. It is used to encode the minimum amount of speech information necessary to reproduce a
perceptible message with a fewer bits that those needed by a conventional encoder/decoder
A. codec
B. muldem
C. vocoders
D. modem
228. It is the transmission of information in any form from one source to one or more destination
A. Modulation
B. Multiplexing
C. Encoding
D. Decoding
A. Packet switching
B. Message switching
C. Circuit switching
D. Digital switching
230. In digital modulation, it is similar to standard amplitude modulation except there is only two
amplitudes possible
A. frequency shift keying
231. The technique of using modulation and FDM to transmit multiple data channels of a
common medium is known as
A. baseband
B. broadband
C. ring
D. bus
A. minimizes noise
233. Transmissions from multiple sources occur in the same facility but not at the same time
234. A 9600-baud rate signal can pass over the voice grade telephone line if which kind of
modulation is used?
A. BPSK
B. QPSK
C. DPSK
D. QAM
235. Indicate which of the following pulse modulation systems is analog
A. PCM
B. PWM
C. Differential PCM
D. Delta
B. frequency modulation
C. pulse-position modulation
D. pulse-code modulation
237. It is simply the number of bits transmitted during one second and expressed in bits per
second
A. baud
B. bits
C. bit rate
238. It is the most prevalent encoding technique used for TDM signals
A. PAM
B. PLM
C. PPM
D. PCM
239. The characters making up the message in a synchronous transmission are collectively
referred to as the data
A. set
B. sequence
C. block
D. collection
240. A virtual circuit which is logically equivalent to a two-point dedicated private-line circuit
except slower
A. Noise
B. Fading
C. A jamming signal
D. An intermittent connection
A. Digital phone
B. Picturephone
C. Cameraphone
B. simplicity
C. lower cost
A. balanced modulator
B. shift register
C. binary adder
D. multiplexer
A. information
B. data
C. symbol
D. intelligence
246. Which of the following words has the correct parity bit? Assume odd parity. The last bit is
the parity bit.
A. 1111111 1
B. 1100110 1
C. 0011010 1
D. 0000000 0
247. It is a digital interface that provides the physical connection to the digital carrier network
A. Modem
B. Codec
C. Muldem
D. DSU/CSU
248. It is the only digitally encoded modulation technique that is commonly used for digital
transmission
A. PAM
B. PCM
C. PLM
D. PPM
249. The most common circuit used for demodulating binary FSK signals
C. varactor
A. PSK
B. FSK
C. QUAM
D. OOK
MISCELLANEOUS TOPICS
Electronics Systems and Technologies
By
Melvin C. Arceo
ENCODED BY:
GIRAO, Edward Joseph D.
1. It is the provision of voice communication using Internet Protocol (IP) technology, instead of
traditional circuit switched technology
A. VOIP
B. Bluetooth
C. WIFI
D. WIMAX
2. Bluetooth enabled electronic devices connect and communicate wirelessly through short-
range, ad hoc networks known as _____.
A. nanonet
B. scatternet
C. piconet
D. netnet
3. Each device can simultaneously communicate with up to ______ other devices with a single
piconet.
A. 8
B. 5
C. 10
D. 7
4. The core specification version of Bluetooth that uses Enhanced Data Rate (EDR)
A. Version 1.0
B. Version 2.0
C. Version 1.2
D. Version 2.1
A. ISM
B. C band
C. MSI
D. Ku band
A. 1000 hops/sec
B. 1600 hops/sec
C. 1500 hops/sec
D. 2500 hops/sec
B. DSSS
C. OFDM
D. FHSS
9. The signal hops among ______ frequencies at 1 MHz intervals to give a high degree of
interference immunity
A. 80
B. 78
C. 81
D. 79
A. 1 ft
B. 2 ft
C. 3 ft
D. 4 ft
11. Class 2 radios used for Bluetooth most commonly found in mobile devices have a range of
______.
A. 10 ft
B. 20 ft
C. 15 ft
D. 30 ft
12. Class 1 radios used primarily in industrial use cases have a range of
A. 100 meters
B. 25 meters
C. 10 meters
D. 50 meters
13. Bluetooth technology uses ______ of power.
A. 2.6 mW
B. 2.5 mW
C. 2,8 mW
D. 2.7 mW
14. What is the data rate used by Bluetooth technology using version 1.2 specification?
A. 1 Mbps
B. 2 Mbps
C. 3 Mbps
D. 4 Mbps
15. What is the data rate used by Bluetooth technology using version 2.0 + EDR specification?
A. 1 Mbps
B. 3 Mbps
C. 2 Mbps
D. 4 Mbps
16. Bluetooth technology has built-in security such as _____ bit encryption
A. 64
B. 16
C. 32
D. 128
A. 0
B. 5
C. 15
D. 3
19. An international agreement initially mandated that all satellites placed in the Clarke or
Geosynchronous orbit must be separated by at least
A. 22,300 mi
B. 3400 mi
C. 1833 mi
D. 5544 mi
20. The radiation pattern of earth coverage antennas of satellites have a beamwidth of
approximately ______.
A. 15 degrees
B. 17 degrees
C. 10 degrees
D. 11 degrees
21. ______ is a new nonvoice value added service that allows information to be sent and
received across a mobile telephone network.
A. WiFi
B. Wimax
C. GPRS
D. HSCSD
22. Theoretical maximum speeds of up to _____ kbps are achievable with GPRS using all _____
timeslots at the same time.
A. 64, 8
B. 171.2, 8
C. 128, 7
D. 183.5, 7
23. It is the latest standard of MPEG under development that will support download and
execution of multimedia applications.
A. MPEG-21
B. MPEG-A
C. MPEG-7
D. MPEG-E
24. A new standard line of MPEG standard called multimedia application format is _____.
A. MPEG-A
B. MPEG-C
C. MPEG-B
D. MPEG-D
25. MPEG standard on which such products as Digital Television set top boxes and DVD are
based
A. MPEG-1
B. MPEG-4
C. MPEG-2
D. MPEG-7
26. MPEG standard on which such products as Video CD and MP3 are based
A. MPEG-1
B. MPEG-7
C. MPEG-21
D. MPEG-3
27. MPEG standard for multimedia for the fixed and mobile web
A. MPEG-1
B. MPEG-4
C. MPEG-2
D. MPEG-7
28. MPEG standard for description and search of audio and visual content.
A. MPEG-1
B. MPEG-7
C. MPEG-21
D. MPEG-3
A. M3W
B. MPEG-4
C. MPEG-7
D. MPEG-21
30. Coding of moving pictures and associated audio for digital storage media at up to about 1.5
Mbps.
A. MPEG-3
B. MPEG-2
C. MPEG-4
D. MPEG-1
A. Digital television
B. Interactive multimedia
D. Any of these
A. 0.5 watt
B. 3 watts
C. 1 watt
D. 0.25 watt
34. The use and operation of RFIDs shall be allowed in the following frequency bands except:
A. 13.533-13.567 MHz
B. 2446-2454 MHz
C. 918-920 MHz
D. 254-365 MHz
35. _____ are radio systems based on local area networking solutions that require higher data
rates and consequently greater bandwidth for new multimedia applications spectrum
requirements
A. WIFI
B. HiperLAN
C. WIMAX
D. VOIP
36. _____ refers to the determination of the position, velocity and/or other characteristics of an
object, or the obtaining of information relating to these parameters, by means of the propagation
properties of radio waves.
A. position determination
B. radio determination
C. velocity determination
D. range determination
A. 20
B. 40
C. 30
D. 50
38. _____ referred to as wireless microphones or cordless microphones, are small, low power,
unidirectional transmitters designed to be worn on the body, or hand held, for the transmission of
sound over short distances for personal use.
A. directional microphone
B. parabolic microphone
C. radio microphone
D. spy microphone
39. _____ are intended to carry data in suitable transporters, generally known as tags, and to
retrieve data, by hand- or manine-readable means, at a suitable time and place to satisfy
particular application needs.
A. RFID
B. HiperLan
C. transponder tags
D. bluetooth
40. _____ also referred to as dedicated short-range communications for transport information
and control systems are systems providing data communication between two or more road
vehicles and between road vehicles and the road infrastructure for various information-based
travel and transport applications, including automatic toll-collection, route and parking guidance,
collision avoidance and similar applications.
A. RTTY
B. TICS
C. RTTT
D. RSSD
41. _____ for use with implanted medical devices, like pacemakers, implantable defibrillators,
nerve stimulators, and other types of implanted devices.
A. MICS
B. TICS
C. AIDS
D. PACER
A. 40.66-40.70 MHz
B. 13.90-14.40 MHz
C. 50.44-51.09 MHz
D. 32.10-33.89 MHz
A. 1000 V/m at 3m
B. 10 V/m at 3m
C. 100 V/m at 3m
D. 1 V/m at 3m
44. _____ refers to the use of radio communication devices for the transmission of signals to
initiate, modify or terminate functions of equipment at a distance.
A. telemetry
B. wireless application
C. telecommand
D. radio beacon
A. 11 Mbps
B. 55 Mbps
C. 54 Mbps
D. 12 Mbps
A. 2.4 GHz
B. 5.5 GHz
C. 5 GHz
D. 2.5 GHz
A. 2.5 GHz
B. 5 GHz
C. 5.5 GHz
D. 2.1 GHz
A. 55 Mbps
B. 53 Mbps
C. 54 Mbps
D. 50 Mbps
A. Wimax
B. Wibro
C. Wifi
D. Winar
50. _____ is a wireless broadband technology being developed by the Korean telecoms industry.
A. Wimax
B. Wibro
C. Wifi
D. Winar
A. 2.1 GHz
B. 2.3 GHz
C. 2.2 GHz
D. 2.4 GHz
A. 30 to 50 Mbps
B. 40 to 60 Mbps
C. 50 to 70 Mbps
D. 60 to 80 Mbps
A. 2 km
B. 3 km
C. 4 km
D. 5 km
54. _____ is a published specification set of high level communication protocols designed to use
small, low-power digital radios based on the IEEE 802.15.4 standard for wireless personal area
networks.
A. bluetooth
B. wpan
C. zigbee
D. wlan
55. In a Zigbee network, a single device that controls the network is called _____.
A. master
B. server
C. coordinator
D. pointer
A. end devices
B. clients
C. slaves
D. beggars
A. OFDM
B. CCK
C. QPSK
D. FDM
A. OFDM
B. CCK
C. QPSK
D. FDM
59. The World Wide Web or WWW was invented in the year _____.
A. 1991
B. 1990
C. 1989
D. 1995
60. He invented the World Wide Web or WWW
A. Karel Capek
B. Tim Berners-Lee
D. Bill Gates
A. 30
B. 26
C. 24
D. 31
A. EDGE
B. HSCSD
C. VOIP
D. 3GSM
A. 16,000 feet
B. 8,000 feet
C. 18,000 feet
D. 12,000 feet
64. ______ is an implementation of ADSL that automatically adjusts the connection speed to
adjust for the quality of the telephone line.
A. ADSL
B. SDSL
C. RADSL
D. HDSL
65. A type of DSL that was developed to support exceptionally high-bandwidth applications such
as High-Definition Television (HDTV).
A. VDSL
B. SDSL
C. ADSL
D. XDSL
66. A method for moving data over regular phone lines which is much faster than a regular phone
connection and the wires coming into the subscribers premises are the same copper wires used
for regular phone service.
A. VOIP
B. DSL
C. Cable Internet
D. POTS
A. 802.15
B. 802.14
C. 802.10
D. 802.16
A. 802.12
B. 802.13
C. 802.5
D. 802.11
A. 802.16
B. 802.15
C. 802.14
D. 802.13
A. .jpg
B. .jpe
C. .jfif
D. any of these
71. In SMS, the number of characters being sent in the network is _____ when Latin alphabet is
used.
A. 80
B. 160
C. 65
D. 100
72. In SMS, the number of characters being sent in the network is _____ when non-Latin
alphabet is used.
A. 50
B. 60
C. 70
D. 80
73. It is an enhancement of data services of all current GSM networks, it allows you to access
nonvoice services at 3 times faster
A. GPRS
B. HSCSD
C. VOIP
D. 3GSM
74. A language derived from HTML especially for wireless network characteristics.
A. Delphi
B. PHP
C. Pearl
D. WML
A. Tim Burners-Lee
D. Carel Kapek
76. What term is used by in asynchronous transfer mode (ATM) system to describe a byte?
A. harmonic
B. octet
C. actave
D. bit
A. 11.7
B. 1.17
C. 1.18
D. 11.8
78. One of the following is NOT classified as a Customer Premises Equipment (CPE) by the
NTC.
C. VSAT
D. ISDN Terminal Equipment
A. tree
B. bus
C. star
D. mesh
C. network-based or device-based
D. feature-based or attachment-based
81. The level of ____ within an IM program brings up the issue of privacy.
A. users signed up
B. advertising
C. technology
D. presence awareness
82. One reason behind the success of the Internet is the fact that it is built on _____.
A. open standard
B. user trust
C. safe architecture
D. solid ground
83. Which of the following is not an additional revenue opportunity offered by advance
messaging services?
A. electronic commerce
B. advertising
C. targeted marketing
D. taxes
A. twofold
B. threefold
C. thirtyfold
D. fiftyfold
85. What appears to be the practical limit for analog modems over a standard telephone?
A. 33 kbps
B. 28.8 kbps
C. 24 kbps
D. 19.2 kbps
86. Which of the parameters will need to be incorporated into next generation billing solutions to
calculate new 3G charges?
A. number of packets
B. location
C. quality of service
D. any of these
A. streaming video
B. wireless voice
C. interactive shopping
A. 3
B. 4
C. 32
D. 64
89. All are required for broadband media services delivery over IP except:
A. high bandwidth
B. a broadband connection
C. a narrowband connection
D. DSL
90. All are network components for broadband media services except
A. video server
B. catv box
C. set-top box
D. video encoder
91. A Cable Modem Termination System (CMTS) provides an Ethernet network with a
geographic reach of up to _____.
A. 1 mile
B. 10 miles
C. 100 miles
D. any of these
92. The upstream data channel specification requirement for cable modem feature which of the
following?
C. 6 MHz-occupied spectrum that coexists with other signals in the cable plant
93. DWDM enables different formats, such as ______, to be transmitted over the optical layer.
A. IP and ATM
94. Future DWDM terminals will have the capacity to transmit _____ volumes of an
encyclopedia in one second.
A. 90
B. 250
C. 1500
D. 90000
95. DWDM allows the transmission of _____ over the optical layer.
C. data
96. Which of the following is expected to take the largest share of the three DSL varieties?
A. SDSL
B. HDSL
C. ADSL
D. IDSL
97. Which of the following standards defines procedures and message sequences used for fax
communications?
A. T.10
B. T.30
C. T.37
D. T.38
98. The _____ is a particular set of standards that allows the internetworking of products from
different vendors. It usually embodies a fiber-optic ring that will permit transmission in both
directions.
B. control signaling
C. call signaling
B. control signaling
103. One of the major advances that result from implementing intelligent networks is that _____.
104. The development of the intelligent network places increased emphasis on a consistent
_____.
A. switch model
B. network model
C. intelligence model
D. call model
105. How many layers are there to the PCS air resistance?
A. 1
B. 2
C. 3
D. 4
A. 64
B. 256
C. 1021
D. 239
107. Signaling units are broken up into units of how many bits?
A. 8
B. 16
C. 32
D. 64
108. Two digital signals whose transitions occur at almost the same rate are _____.
A. asynchronous
B. synchronous
C. plesiochronous
D. none of these
109. Which of the following are not basic SONET network elements?
A. switch interference
D. add/drop multiplexer
A. 1.5 Mbps
B. ATM cells
A. 1
B. 3
C. 6
D. 10
113. The G.723.1 specification for audio codecs, recommended by the VoIP Forum, requires:
A. 6.3 kbps
B. 7.9 kbps
C. 8.4 kbps
D. 10.4 kbps
114. ITUs H.320 standard defines the protocols for transporting voice, data and video over;
A. PSTN
B. ISDN networks
D. GSM network
115. Which of the following is not a layer in the WAP gateway stack?
A. WDP
B. context manager
C. TCP
D. WSP
116. Queries to the HLR are performed to find the location of the serving MSC in _____.
A. TDMA
B. CDMA
C. GSM
A. HLR
B. VLR
C. MSC
D. BSC
119. Which of the following technologies has significant advantages in medium-density and
high-density population areas because it is capable of carrying higher levels of traffic, provides
better voice quality, and can transmit data at higher rates?
A. GSM
B. PCS
C. CT-2
D. DECT
120. IS-41 is a standard currently being embraced by wireless providers because it encourages
_____.
B. paging
C. roaming
CELLULAR TELEPHONY
Electronics Systems and Technologies
By
Melvin C. Arceo
ENCODED BY:
LAQUI, Louise Ruelyn J.
1. Base station transmitter output power of Improved Mobile System (IMTS)
A. 3.84 Mcps
B. 3.6484 Mcps
C. 1.25 Mcps
D. 1.22 Mcps
3. A technique that divides the group of channels into smaller groupings or segments of
mutually exclusive frequencies; cell sites, which are within the reuse distance is assigned
their own segment of the channel group
A. sectoring
B. dualization
C. partitioning
D. segmentation
4. The actual voice channel where mobile users communicate directly with other mobile
or wireline subscriber through the base station
A. control channel
B. forward channel
C. reverse channel
D. voice channel
A. 5940 Hz
B. 5970 Hz
C. 6000 Hz
D. 6030 Hz
A. Repeater
B. Control computer
C. Direct-link to a branch exchange
D. Touch-tone processor
A. -6dBW
B. -4dBW
C. 2dBW
D. 6dBW
A. 2.5 MHz
B. 3 MHz
C. 4.5 MHz
D. 5MHz
9. An automobile travels at 60km/hr. Find the time between fades in the car uses a PCS
phone at 1900 MHz.
A. 2.4 ms
B. 3.4 ms
C. 4.7 ms
D. 5.1 ms
10. A cellular system is capable of coping with handoffs once every 2 minutes. Suppose this
system is in the city with maximum car speeds of 65km/hr. What is the maximum cell
radius for this urban system?
A. 1.08 km
B. 3 km
C. 5 km
D. 2 km
A. 16 kHz
B. 200 kHz
C. 100 kHz
D. 50 kHz
12. Changing the time order of digital information before transmission to reduce the effect of
burst errors in the channel.
A. progression
B. interleaving
C. epoch
D. raking
A. 5
B. 15
C. 20
D. 25
14. It is the process in which the same set of frequencies can be allocated to more than one
cell, provided that the cells are separated by a sufficient distance
A. frequency reuse
B. handoff
C. clustering
D. radio survey
15. A connection is momentarily broken during the cell-to-cell transfer is called ______.
A. hard handoff
B. soft handoff
C. medium handoff
D. light handoff
A. forward link
B. reverse link
C. control link
D. user link
17. It is a database in the PCS network that stores information about the user, including home
subscription information and what supplementary services the user is subscribed to.
18. Determine the transmit power for a CDMA mobile unit that is receiving a signal from the
base station at 100 dBm
A. 12 dBm
B. 24 dBm
C. 36 dBm
D. 14 dBm
19. When transmitting digital information, voice transmission is inhibited, this is called
______.
A. quieting
B. muting
C. blank-and-burst
D. any of these
20. A metropolitan area of 1000 square km is to be covered by cells with a radius of 2 km.
How many cell sites would be required, assuming hexagonal cells?
A. 72
B. 73
C. 74
D. 75
A. coast station
B. maritime station
C. coast earth station
D. ship earth station
A. Color code
B. Walsh code
C. PCS code
D. CDMA
23. In a spread spectrum system, the tendency for a stronger signals to interfere with the
reception of weaker signals.
A. near-far field
B. near-far effect
C. direct-sequence
D. spread-spectrum
A. 3W to 7W
B. 1W to 6W
C. 2W to 8W
D. 0.1W to 5W
25. It is when the area of a cell, or independent component coverage areas of a cellular
system, is further divided, thus creating more cell areas.
A. cell splitting
B. cell clustering
C. cell partitioning
D. cell sectoring
26. It is when a mobile unit moves from one cell to another from one company's service area
to another company's service area.
A. roaming
B. handoff
C. handover
D. paging
27. It is a 34-bit binary code that represents the 10-digit telephone number
A. 4
B. 5
C. 6
D. 7
A. 870.36 MHz
B. 870.63 MHz
C. 870.96 MHz
D. 870.69 MHz
30. In mobile wireless communication, the radio equipment and the propagation path
A. FSL
B. air interface
C. direct link
D. mobile interface
31. The signaling fone may be transmitted on the voice channel during a call in what
frequency?
A. 25 kHz
B. 20 kHz
C. 15 kHz
D. 10 kHz
32. Station in the mobile service not intended to be used while in motion.
A. base station
B. fixed station
C. coast station
D. land station
33. In the GSM system, a "smart card" containing all user information, which is inserted into
the phone before use.
A. IMSI
B. IMEI
C. IMTS
D. SIM
34. Determine the number of channels per cluster of a cellular telephone area comprised of
10 clusters with seven cells in each cluster and 10 channels in each cell.
35. Determine the channel capacity if 7 macrocells with 10 channels per cell is split into 4
minicells
36. Technique of spread spectrum that breaks message into fixed-size blocks of data with
each block transmitted in sequence except on the different carrier frequency.
A. spread spectrum
B. time-division multiplexing
C. frequency-hopping
D. direct sequence
37. A base and mobile is separated by 5 km. What is the propagation time for a signal
traveling between them?
A. 14.5 usec
B. 18.9 usec
C. 20.8 usec
D. 16.7 usec
A. MIN
B. ESN
C. SAT
D. SIM
39. A new regulation issued by the National Telecommunications Commission providing for
the guideline for mobile personal communication having a global coverage using
satellite.
A. NMT
B. GMPCS
C. GSM
D. TACS
A. 3
B. 7
C. 12
D. 15
41. Provides a centralized administration and maintenance point for the entire network end
interfaces with the public telephone network through the telephone wireline voice trunks
and data links
A. PSTN
B. MTSO
C. central offices
D. MSC
42. It is a digital telephone exchange located in the MTSO that is the heart of a telephone
system
43. A database in the PCS network that stores information pertaining to the identification and
type of equipment that exist in the mobile unit.
A. visitor location register
B. home location register
C. equipment identification register
D. authentication register
44. When a signal from a mobile cellular unit drops below a certain level, what action
occurs?
45. A method of transmitting data on AMPS cellular telephone voice channels that are
temporary unused.
46. A vehicle travels through a cellular system at 100 km per hour. Approximately how often
will handoffs occur if the cell radius is 10 km.
A. 12 min
B. 14 min
C. 16 min
D. 18 min
47. In the GSM system, a telephone number that is unique to a given user, worldwide.
A. IMTS
B. IMEI
C. IMSI
D. SIM
48. An area divided into hexagonal shapes that fit together to form a honeycomb pattern is
called ______.
A. cluster
B. transport area
C. cell
D. area of responsibility
49. Determine the channel capacity of a cellular telephone area comprised of twelve
macrocell with ten channels per cell
A. forward link
B. reverse link
C. control link
D. user link
A. user or caller
B. cell site
C. called party
D. MTSO
A. 250 kHz
B. 200 kHz
C. 150 kHz
D. 100 kHz
53. A switching facility connecting cellular telephone base stations to each other and to the
public switched telephone network.
A. MTSO
B. MSC
C. VLR
D. AuC
A. land station
B. ship earth station
C. base station
D. mobile station
55. Transmission of brief text messages, such as pages or e-mail, by cellular radio or PCS.
A. SMS
B. MMS
C. paging
D. raking
56. The point when the cell reaches maximum capacity occurs when the number of
subscribers wishing to place a call at any given time equals the number of channels in the
cell
A. saturation
B. blocking traffic
C. maximum traffic load
D. any of these
57. In IS-41 standard, it is a process where the mobile unit notifies a serving MTSO of its
presence and location through a base station controller.
A. dependent registration
B. autonomous registration
C. air interface
D. BTS to BSC interface
A. simplex
B. half-duplex
C. full-duplex
D. triplex
59. A receiver capable of receiving several versions of the same signal with different arrival
times and combining the received versions into a single signal with better quality
A. scanners
B. rake receivers
C. mobile subscriber unit
D. mobile stations
A. VLR
B. HLR
C. BTS
D. AUC
61. In CMTS, the number of duplex voice channels for AMPS is ____.
A. 676
B. 285
C. 395
D. 790
62. A geographic cellular radio coverage area containing three of more group of cells
A. cluster
B. cell
C. radio channel
D. MSC/VLR area
A. hard handoff
B. soft handoff
C. heavy handoff
D. light handoff
A. 32
B. 15
C. 10
D. 8
65. The RF power output of a transmitter in a cellular mobile telephone system authorized by
NTC for use in the Philippines.
A. 20.5 dBm
B. 31.5 dBm
C. 34.8 dBm
D. 22.1 dBm
A. 4W
B. 1.6 W
C. 600 mW
D. 1.4 W
67. ____ is measuring the propagated field strength over the projected service area.
A. radio monitoring
B. radio sounding
C. radio survey
D. none of these
68. Transmission of data in two directions on a channel by using different time slots for each
directions.
A. time-division multiplexing
B. time-division multiple access
C. time-division duplexing
D. time-division
69. When the cluster size is reduced with a constant cell size, what happens to the total
channel capacity?
A. decreases
B. increases
C. stays constant
D. depends on the number of cell cites
70. The transfer of a mobile unit from one base station's control to another base station's
control
A. handoff
B. paging
C. roaming
D. dualization
A. 12 kHz
B. 6 kHz
C. 3 kHz
D. 18 kHz
A. 2
B. 3
C. 4
D. 5
73. A transmit channel has a frequency of 837.6 MHz. The receive channel frequency is
A. 729.6 MHz
B. 837.6 MHz
C. 867.6 MHz
D. 882.6 MHz
74. A frequency-hopping spread-spectrum system hops to each of 100 frequencies every 10
seconds. How long does it spread on each frequency?
A. 0.2 sec/hop
B. 0.4 sec/hop
C. 0.3 sec/hop
D. 0.1 sec/hop
A. 128 kbps
B. 240 kbps
C. 64 kbps
D. 270 kbps
76. A card with an embedded integrated circuit that can be used for functions such as storing
subscriber information for a PCS system.
A. smart card
B. SIM
C. Intelligent card
D. Credit card
77. It is a means of avoiding full-cell splitting where the entire area would otherwise need to
be segmented into smaller cells.
A. segmentations
B. dualization
C. sectoring
D. splitting
78. A channel used for transferring control and diagnostic information between mobile users
and a central cellular telephone switch through the base stations.
A. forward channel
B. voice channel
C. control channel
D. reverse channel
79. It is the provision of voice communication using internet protocol technology, instead of
traditional circuit switched technology.
A. WAP
B. GPRS
C. VOIP
D. WIFI
80. Determine the total number of channel capacity of a cellular telephone area comprised of
10 clusters with seven cells in each cluster and 10 channels in each cell.
A. 7 channels
B. 70 channels
C. 700 channels
D. 7000 channels
81. Technique used in spread spectrum that adds a high-bit rate pseudorandom code to a low
bit rate information signal to generate a high-bit rate pseudorandom signal closely
resembling noise that contains both the original data signal and pseudorandom noise.
A. direct-sequence
B. frequency-division multiplexing
C. frequency hopping
D. CDMA
82. Refers to the first generation of local loop system in telecommunication technology
A. TACS
B. DECT
C. Analog cellular
D. GSM
83. An information sent by the base station in a cellular radio system set the power level of
the mobile transmitter.
85. It serves as central control for all users within that cell
A. base stations
B. antennas
C. transceivers
D. mobile subscriber units
86. What modulation technique is used by Advanced Mobile Phone System (AMPS)
A. WBFM
B. VSB
C. NBFM
D. FSK
87. A database in the PCS network that stores information about subscribers in a particular
MTSO serving area
88. In cellular phone, a memory location that stores the telephone number(s) to be used on
the system.
A. EPROM
B. UVPROM
C. EEPROM
D. NAM
89. A province in the Philippines has an area 2000 sq. kms. It has to be covered by a cellular
mobile telephone service using cells with a radius of 3 kms. Assuming hexagonal cells,
find the number of cell sites needed.
A. 100
B. 500
C. 166
D. 145
A. QAM
B. Phase Shift Keying
C. Gaussian Minimum Shift Keying
D. Frequency Shift Keying
A. 0.4W to 0.7W
B. 1W to 6W
C. 0.5W to 8W
D. 0.1W to 1W
92. Determine the receive carrier frequencies for AMPS channel 3 and channel 991
A. clustering
B. splitting
C. partitioning
D. sectoring
94. Soft handoff normally takes ____ of time delay.
A. 400 ms
B. 300 ms
C. 200 ms
D. 100 ms
95. Component of a cellular telephone network that manages each of the radio channels at
each site.
A. 4
B. 5
C. 8
D. 10
97. The master control center for a cellular telephone system is the
A. Cell site
B. MTSO
C. Central office
D. Branch office
A. 6 kHz
B. 12 kHz
C. 30 kHz
D. 45 kHz
99. A receiver channel has a frequency is 872.4 MHz. to develop an 82.2 MHz IF, the
frequency synthesizer must apply an local oscillator signal of ____ (The local oscillator is
usually higher than the receive frequency)
A. 790.2 MHz
B. 827.4 MHz
C. 954.6 MHz
D. 967.4 MHz
A. 6 dBW
B. 2 dBW
C. -2 dBW
D. -6 dBW
101. A mobile telephone service using trunked channels but not cellular nature
A. IMTS
B. MTSO
C. IMSI
D. IMEI
102. The GSM cellular radio system uses GMSK in a 200-kHz, with a channel data
rate of 270.833 kbps. Calculate the frequency shift between mark and space in kHz?
A. 135.4165
B. 153.6514
C. 315.4651
D. 513.1654
103. A cellular system is capable of coping with a handoffs once every 2 minutes.
What is the maximum cell radius if the system must be capable of working with cars
traveling at highway speed of 120 km/hr?
A. 3 km
B. 1 km
C. 4 km
D. 6 km
104. Radio communication operation service between mobile and land stations or
between mobile stations.
A. land mobile
B. land mobile satellite service
C. mobile service
D. maritime mobile service
A. FDMA
B. CDMA
C. TDMA
D. TACS
106. This is the Nordic analog mobile radio telephone system originally used in
Scandinavia
A. NMT
B. GSM
C. PCN
D. PCS
107. The combination of the mobile cellular phone and the cell-site radio equipment is
known as
A. forward link
B. base transceiver station
C. air interface
D. base station controller
A. 40 MHz
B. 80 MHz
C. 120 MHz
D. 30 MHz
109. The channel separation of GSM channel
A. 270 kHz
B. 200 kHz
C. 120 kHz
D. 60 kHz
A. 25
B. 23
C. 21
D. 19
A. FM
B. FSK
C. TFSK
D. QAM
A. 80 kbps
B. 25 kbps
C. 21 kbps
D. 13 kbps
A. 333
B. 666
C. 124
D. 248
114. It is a database that contains information about the identity of mobile equipment
that prevents calls from stolen, unauthorized, or defective mobile stations.
115. It provides all the control functions and physical links between the MSC and BTS
A. OSS
B. OMC
C. MSC
D. BSC
116. It is the functional entity from which the operator monitors and controls the
mobile communication system.
117. A node in the switching system of GSM that provides integrated voice, fax and
data messaging.
118. It is a node in the switching system of GSM that handles mobile intelligent
network services.
A. Message Center
B. Gateway Mobile Switching Center
C. Mobile Service Unit
D. Mobile Switching Center
119. The modulation scheme used for NADC
A. NFSK
B. Quarterwavelength Shifted QPSK
C. GFSK
D. Trellis coding
SATELLITE
COMMUNICATIONS
Electronics Systems and Technologies
By
Melvin C. Arceo
ENCODED BY:
LAQUI, Louise Ruelyn J.
1. It is a celestial body that orbits around a planet.
A. Primary body
B. Satellite
C. Heavenly bodies
D. Quasars
2. It is a position and timing service that is available to all GPS users on a continuous,
worldwide basis with no direct charge.
A. PPI
B. PPS
C. SPS
D. SSP
A. Ellipse
B. Parabolic
C. Hyperbolic
D. Paraboloid
A. Mixer
B. Local oscillator
C. Bandpass filter
D. HPA
5. The three axes referred to the three-axis attitude stabilization are; except
A. Pitch
B. Yaw
C. Roll
D. Speed
A. 456.45 ms
B. 275.58 ms
C. 137.79 ms
D. 126.89 ms
A. 30,000 km/hr
B. 25,000 mi/hr
C. 35,000 m/s
D. 25,000 km/hr
A. Repeater
B. Transponder
C. Satellite
D. Mixer
9. Calculate the angle of declination for an antenna using a polar mount at a latitude of 45
degrees.
A. 3.2 degrees
B. 1.3 degrees
C. 4.2 degrees
D. 6.81 degrees
10. The time transfer accuracy used with reference to the Universal Transmitter Mercator
Grid is ____.
A. UTC
B. UTMG
C. GMT
D. UTM
11. It is caused by the inertia of the satellite balanced by the earths gravitational pull.
A. Centrifugal force
B. Centripetal force
C. Speed
D. Earths rotation
12. In satellites, it includes control mechanism that support the payload operation.
A. Bus
B. Payload
C. Ground segment
D. Space segment
13. A satellite transmitter operates at a 4 GHz with a transmitter power of 7W and an antenna
gain of 40 dBi. The receiver has antenna gain of 30 dBi, and the path length is 40,000
km. calculate the signal strength at the receiver.
A. -88 dBm
B. -98 dBm
C. -77 dBm
D. -79.8 dBm
14. The satellite subsystem that monitors and controls the satellite is the
A. Propulsion system
B. Power subsystem
C. Communications subsystem
D. Telemetry, tracking, and command subsystems
15. Standard positioning service has time transfer accuracy to Universal Transfer Mercator
Grid within ____.
A. 140 nanoseconds
B. 340 nanoseconds
C. 230 nanoseconds
D. 530 nanoseconds
16. A satellite remains in orbit because the centrifugal force caused by its rotation around the
Earth is counterbalanced by Earths ____.
A. Centripetal force
B. Inertia
C. Gravitational pull
D. Speed
17. A TVRO installation for use with C-band satellite (download frequency at 4 GHz), has a
diameter of about 3.5 meters and an efficiency of 60%. Calculate the gain.
A. 41 dB
B. 19 dB
C. 29 dB
D. 9 dB
18. Which of the following is not a typical output from the GPS receiver?
A. Latitude
B. Speed
C. Altitude
D. Longitude
19. The law that states that a satellite will orbit a primary body following an elliptical path.
20. Telephone communication takes place between two earth stations via a satellite that is
40,000 km from each station. Suppose Bill, at station 1, asks a question and Sharon, at
station 2, answers immediately, as soon as she hears the question. How much time
elapses between the end of Bills question and the beginning of Sharons reply, as heard
by Bill?
A. 0.26 sec
B. 3.2 sec
C. 0.52 sec
D. 1.6 sec
A. Selective availability
B. Reverse error notification
C. Forward error notification
D. Two dimensional reporting
A. AM
B. FM
C. SSB
D. QPSK
A. Law of gravity
B. Law of areas
C. Newtons law of motion
D. Harmonic law
24. A receiving antenna with a gain of 40 dB looks at a sky with a noise temperature of 15 K.
the loss between the antenna and the LNA input, due to the feedhorn is 0.4 dB, and the
LNA has a noise temperature of 40K. Calculate the G/T?
A. 13.4 dB
B. 39 dB
C. 20.6 dB
D. 11.2 dB
25. The operational satellites of Navstar GPS are revolving around Earth in ____ orbital
planes.
A. 4
B. 3
C. 5
D. 6
A. Law of gravity
B. Law of areas
C. Newtons law of motion
D. Harmonic law
28. Calculate the length of the path to a geostationary satellite from an earth station where the
angle of elevation is 30 degrees.
A. 55 x 10^3 km
B. 13 x 10^3 km
C. 23 x 10^3 km
D. 39 x 10^3 km
A. LEO
B. MEO
C. HEO
D. GEO
30. The satellite is orbiting in the same direction as the Earths rotation and at angular
velocity greater than that of the Earth.
A. Retrograde
B. Synchronous
C. Posigrade
D. Asynchronous
31. Find the orbital period of the satellite in a circular orbit 500 km above the Earths surface
A. 1.6 hrs
B. 3.2 hrs
C. 2.4 hrs
D. 6.4 hrs
32. Satellite orbiting in the opposite direction as the Earths rotation and at angular velocity
less than that of the Earth
A. Asynchronous
B. Synchronous
C. Posigrade
D. Retrograde
33. A transponder that demodulates the baseband signals and then demodulates a carrier is
known as ____ transponder.
A. Single-conversion
B. Double-conversion
C. Regenerative
D. Degenerative
34. Low Earth Orbit (LEO) satellite orbits around the earth at a height of approximately
____.
A. 3000 miles
B. 1000 miles
C. 575 miles
D. 370 miles
A. klystron
B. TWT
C. Transistor
D. Magnetron
A. Colorado
B. California
C. Alaska
D. New York
38. Medium Earth Orbit (MEO) satellite orbits around the earth at a height approximately
____.
39. A satellite stays in orbit because the following two factors are balanced
A. HPA
B. Mixer
C. Local oscillator
D. LPA
41. Geosynchronous satellites are high-altitude earth-orbit satellites with heights about ____.
A. 22,300 miles
B. 21,000 miles
C. 8,000 miles
D. 10,400 miles
A. BPF
B. HPA
C. LPA
D. Any of these
A. FDMA
B. OFDMA
C. TDMA
D. CDMA
A. Perigee
B. Apogee
C. Line of apsides
D. Point of shoot
45. Using very narrow beamwidth antennas to isolate signals on the same frequency is
known as ____.
A. Spatial isolation
B. Footprint
C. Frequency reuse
D. Boresight
A. Point of shoot
B. Apogee
C. Line of apsides
D. Perigee
47. The most popular satellite frequency range is 4 to 6 GHz and is called the ____ band.
A. C
B. L
C. Ka
D. Ku
48. All satellites rotate around the earth in an orbit that forms a plane that passes through the
center of gravity of earth called ____.
A. Focus
B. Geocenter
C. Orbit
D. Center
49. In satellite communications, the type of modulation used in voice and video signals is
A. AM
B. FM
C. SSB
D. QPSK
50. In satellite communications, type of orbit which is virtually all orbits except those travel
directly above the equator or directly over the North or the South poles.
A. Equatorial orbit
B. Polar orbit
C. Geosynchronous orbit
D. Inclined orbit
A. 36 MHz
B. 40 MHz
C. 70 MHz
D. 500 MHz
52. It is the angle between the earths equatorial plane and the orbital plane of the satellite
measured counterclockwise.
A. Angle of elevation
B. Angle of azimuth
C. Angle of inclination
D. Angle of tetrahedron
53. Which of the following types of HPA is not used in earth stations?
A. TWT
B. Klystron
C. Transistors
D. Magnetron
A. 880 kg
B. 675 kg
C. 900 kg
D. 540 kg
55. The point where a polar or inclined orbit crosses the equatorial plane traveling from north
to south
A. Ascending node
B. Line of nodes
C. Descending node
D. Diagonal nodes
56. The receive GCE system in an earth station performs what function/s
57. The term generally associated with the table showing the position of a heavenly body on
the number of dates in a regular sequence.
A. Astronomical almanac
B. Smith
C. Ephemeris
D. Space reporting
58. The point where a polar or inclined orbit crosses the equatorial plane traveling from south
to north.
A. Ascending node
B. Descending node
C. Diagonal node
D. Inclined node
59. The line joining the ascending and descending node is called ____.
A. Line of apsides
B. Line of nodes
C. Line of shoot
D. Any of these
60. When the satellite rotates in an orbit directly above the equator, usually in circular
pattern. This type of orbit is called ____.
A. Polar orbit
B. Synchronous orbit
C. Geosynchronous satellite
D. Equatorial orbit
61. The Navstar GPS satellite system was declared fully operational as of ____.
A. TWTs
B. Vacuum tubes
C. Klystrons
D. Magnetrons
64. When the satellite rotates in a path that takes it over the north and south poles in an orbit
perpendicular to the equatorial plane. This type of orbit is called ____.
A. Inclined orbit
B. Polar orbit
C. Geosynchronous orbit
D. Diagonal orbit
65. The azimuth angles and the angle of elevation is collectively known as ____.
66. The point on the surface of the Earth directly below the satellite.
A. Satellite point
B. Latitude
C. Longitude
D. Subsatellite point
67. It is the vertical angle formed between the direction of travel of an electromagnetic wave
radiated from an earth station antenna pointing directly toward a satellite and the
horizontal plane.
A. Angle of depression
B. Angle of inclination
C. Angle of elevation
D. Angle of azimuth
68. The unique number used to encrypt the signal from that of the GPS satellite.
A. SV
B. UV
C. PRN
D. ESN
A. 6 degrees
B. 4 degrees
C. 5 degrees
D. 7 degrees
70. It is the horizontal angular distance from a reference direction either the southern or
northern most point of the horizon.
A. Angle of elevation
B. Latitude
C. Longitude
D. Azimuth
A. Angle of inclination
B. Azimuth angle
C. Latitude
D. Longitude
72. Determines the farthest satellite away that can be seen looking east or west of the earth
stations longitude
A. Radio horizon
B. Optical horizon
C. Terrestrial limits
D. Limits of visibility
A. 3 to 6 degrees
B. 1 to 2 degrees
C. 5 to 8 degrees
D. 8 to 16 degrees
74. The geographical representation of a satellite antennas radiation pattern is called a ____.
A. Field intensity
B. Footprint
C. Radiation propagation
D. Polarization
75. The GPS satellite identification which is assigned according to the order of the vehicles
launch.
A. SV
B. EV
C. PRN
D. ESN
76. The smallest beam of a satellite that concentrates their power to very small geographical
areas.
A. Hemispherical beam
B. Global beam
C. Spot beam
D. Any of these
77. Satellites radiation pattern that typically target up to 20% of the Earths surface.
A. Hemispherical beam
B. Global beam
C. Spot beam
D. Any of these
A. Telemetry
B. Command and Control system
C. On-board computer
D. Transponder
79. The radiation pattern that has a satellites antenna beamwidth of 17 degrees and are
capable of covering approximately 42% of the earths surface.
A. Hemispherical beam
B. Earth beam
C. Spot beam
D. Any of these
A. Moon
B. Sputnik I
C. Score
D. Echo
A. 1 week
B. 21 days
C. 15 days
D. 30 days
A. Syncom
B. Telstar
C. Echo
D. Explorer I
A. 5 months
B. 6 months
C. 12 months
D. 2 months
84. Navstar GPS satellite grouping that can operate continuously for 180 days between
uploads from the ground.
A. Block III
B. Block IIa
C. Block II
D. Block IIR
85. It was the first artificial satellite used for relaying terrestrial communications
A. Score
B. Explorer I
C. Sputnik I
D. Syncom I
86. Which of the following satellite rebroadcast President Eisenhowers 1958 Christmas
message?
A. Telstar I
B. Telstar II
C. Echo
D. Score
87. The satellite or space segment of Navstar GPS is consist of ____ operational satellites.
A. 30
B. 24
C. 14
D. 20
A. Courier
B. Echo
C. Telstar
D. Syncom
A. Telstar I
B. Sputnik I
C. Syncom
D. Courier
90. The first active satellite to simultaneously receive and transmit radio signals.
A. Telstar I
B. Telstar II
C. Intelsat
D. Syncom
92. The satellite that was damaged by radiation from a newly discovered Van Allen Belts and
consequently lasted for two weeks.
A. Telstar I
B. Telstar II
C. Intelsat
D. Syncom
93. As the height of a satellite orbit gets lower, the speed of the satellite
A. Increases
B. Decreases
C. Remains the same
D. None of the above
94. The satellite that was lost in space in its first attempt to place it in a geosynchronous
orbit.
A. Syncom I
B. Telstar I
C. Telstar II
D. Courier
95. Intelsat I which was the first commercial telecommunications satellite is called ____.
A. Domsat
B. Molniya
C. Early bird
D. Courier
96. Block II Navstar GPS satellites can operate for approximately ____ between the
receiving updates and corrections from the control segment of the system.
A. 5.5 days
B. 3.5 days
C. 6 days
D. 7 days
98. It is the time it takes earth to rotate back to the same constellation
A. Revolution
B. Rotation
C. Sidereal period
D. Year
99. Satellites with orbital pattern like Molniya are sometimes classified as
A. LEO
B. MEO
C. GEO
D. HEO
A. Satellite keeping
B. Station controlling
C. Station keeping
D. Satellite controlling
101. Navstar GPS satellite grouping capacble of detecting certain error conditions, then
automatically transmitting a coded message indicating that it is out of service.
A. Block I
B. Block IIa
C. Block II
D. Block IIR
A. > 12 years
B. > 15 years
C. > 20 years
D. > 25 years
A. 100 mi
B. 6800 mi
C. 22,300 mi
D. 35,860 mi
104. An orbit that is 36,000 km away from the geocenter of the earth is called
A. Geosynchronous orbit
B. Clarke orbit
C. Clarke belt
D. Any of these
A. Repeater
B. Reflector
C. Beacon
D. Observation platform
106. Navstar GPS grouping intended to be used only for self testing.
A. Block I
B. Block III
C. Block II
D. Block IIR
A. Footprint
B. Boresight
C. Angle of elevation
D. Angle of azimuth
108. A circular orbit around the equator with 24-h period is called
A. Elliptical orbit
B. Geostationary orbit
C. Polar orbit
D. Transfer orbit
109. A classification of satellite that uses the angular momentum of its spinning body
to provide roll and yaw stabilization.
A. Frequency reuse
B. Polarization
C. Multi-accessing
D. Interference
112. It implies that more than one user has an access to one or more radio channels
A. Co-channel interference
B. Satellite multi-accessing
C. Frequency reuse
D. Diversity
A. Batteries
B. Solar cells
C. Fuel cells
D. Thermoelectric generators
114. A type of satellites multiple-accessing method that allows all users continuous
and equal access of the entire transponder bandwidth by assigning carrier frequencies on
a temporary basis using statistical assignment process.
A. TDMA
B. FDMA
C. DAMA
D. CDMA
116. The highly accurate timing clocks onboard the GPS satellite.
A. Plutonium clocks
B. Cesium atomic clocks
C. Hydrogen clocks
D. Fossil clocks
117. It is defined as the art or science of plotting, ascertaining, or directing the course
of movement.
A. Ranging
B. Detection
C. Navigation
D. Driving
A. 5 circular orbits
B. 3 circular orbits
C. 2 circular orbits
D. 6 circular orbits
A. Perigee
B. Apex
C. Zenith
D. Apogee
A. Wandering
B. Celestial navigation
C. Piloting
D. Radio navigation
A. Main attitude
B. Put the satellite into transfer orbit
C. Inject the satellite into the geosynchronous orbit
D. Bring the satellite back to earth
122. A method of navigation where direction and distance are determined from
precisely timed sightings of celestial bodies, including the stars and the moon.
A. Electronic navigation
B. Heavenly navigation
C. Radio navigation
D. Celestial navigation
A. 20
B. 6
C. 12
D. 18
A. Dead reckoning
B. Radio navigation
C. Wandering
D. Piloting
125. How can multiple earth stations share a satellite on the same frequencies?
A. Frequency reuse
B. Multiplexing
C. Mixing
D. They cant
A. Piloting
B. Wandering
C. Radio navigation
D. Dead reckoning
128. The average elevation of Navstar GPS satellite is ____ statue miles above the
Earth.
A. 6724
B. 7689
C. 5978
D. 9476
A. L
B. C and Ku
C. X
D. S and P
A. If two earth stations do not face a common satellite, they should communicate via a
double-satellite hop.
B. Satellites are allocated so that it is impossible for two earth stations not to face the
same satellite.
C. Collocated earth stations are used for frequency diversity.
D. Satellite earth station must have as many receive chains as there are carriers
transmitted to it.
A. Comsat
B. Domsat
C. Marisat
D. Intelsat
132. Identical telephone numbers in different parts of the country are distinguished by
their
A. Language digits
B. Access digits
C. Area codes
D. Central office codes
133. The GPS satellites has an angle of elevation at the ascending node of ____ with
respect to the equatorial plane.
A. 30 degrees
B. 55 degrees
C. 50 degrees
D. 45 degrees
A. TAT-7
B. INTELSAT V
C. ATLANTIS
D. CANTAT 2
A. 36 MHz
B. 40 MHz
C. 70 MHz
D. 500 MHz
137. The operational satellites of Navstar GPS are revolving around Earth in orbital
planes are approximately ____ degrees apart with ____ satellites in each plane.
A. 60, 4
B. 30, 5
C. 50, 5
D. 40, 3
A. INTELSAT
B. TELSTAR
C. COMSAT
D. INMARSAT
A. LNA
B. Mixer
C. Modulator
D. HPA
A. John Glenn
B. Neil Armstrong
C. Yuri Gagarin
D. Edwin Aldrin
141. It refers to the satellite orientation with respect to the earth.
A. Satellites attitude
B. Satellite position
C. Satellite location
D. Satellite orbit
142. Precise positioning service has time transfer accuracy to UTC within
A. 100 nanoseconds
B. 300 nanoseconds
C. 200 nanoseconds
D. 400 nanoseconds
143. The fully deployed Galileo satellite system consists of ____ satellites.
145. Galileo satellites are at circular planes at ____ altitude above Earth.
A. 23,500 mi
B. 36,500 km
C. 35,800 mi
D. 23,222 km
146. Galileo satellites are inclined at the orbital planes of ____ with reference to the
equatorial plane.
A. 64 degrees
B. 17 degrees
C. 56 degrees
D. 34 degrees
MULTIPLE CHOICE QUESTIONS IN
ANTENNA
Electronics Systems and Technologies
By
Melvin C. Arceo
ENCODED BY:
LORENZO, Luer Breech B.
1) It is a metallic conductor system capable of radiating and capturing electromagnetic energy.
a) transmission lines
b) antenna
c) waveguides
d) load
3) The ratio of the focal length to the diameter of the mouth of the parabola is called _____.
a) aperture
b) focal point
c) foci
d) major axis
5) A special type if transmission lint that consists of a conducting metallic tube through which
high-frequency electromagnetic energy is propagated.
a) medium
b) microstrip
c) stripline
d) waveguide
6) Calculate the angle of declination for an antenna using a polar mount at a latitude of 45
degrees.
a) 3.2 degrees
b) 1.3 degrees
c) 4.2 degrees
d) 6.81 degrees
7) The cone angle of the flare angle of a conical horn antenna is approximately
a) 55 degrees
b) 45 degrees
c) 40 degrees
d) 50 degrees
8) Electrical energy that has escaped into free space in the form of transverse electromagnetic
waves
a) radio waves
b) frequency
c) signal
d) wavelength
10) Using a small reflector to beam waves to the larger parabolic reflector is known as
a) focal feed
b) horn feed
c) cassegrain feed
d) coax feed
11) The plane parallel to the mutually perpendicular line in the electric and magnetic fields is
called _____
a) wavefront
b) point source
c) isotropic source
d) rays
12) What is the beamwidth of a parabolic antenna with a diameter of 5 meters and an operating
frequency to 10 GHz?
a) 0.5 degrees
b) 0.675 degrees
c) 0.348 degrees
d) 3.48 degrees
16) Calculate the gain of a parabolic antenna using a 2.5-m radius dish operating at 10 GHz.
a) 166.673 dB
b) 83.7 dB
c) 52.2 dB
d) 45.6 dB
18) The feed mechanism in a parabolic antenna that radiates the electromagnetic energy
a) primary antenna
b) reflectors
c) secondary antenna
d) focal point
19) It is a polar diagram representing field strengths or power densities at various angular
relative to an antenna
a) sidelobe
b) front lobe
c) radiation pattern
d) radiation constant
20) For a transmit antenna with a radiation resistance of 72 ohms, an effective antenna resistance
of 8 ohms, a directivity gain of 20 and an input power of 100W, determine the antenna gain.
a) 12.55 dB
b) 10.43 dB
c) 11.21 dB
d) 9.78 dB
21) The radiation pattern plotted in terms of electric field strength or power density
a) absolute radiation pattern
b) relative radiation pattern
c) absolute front lobe pattern
d) absolute sidelobe pattern
24) What must be the height nof a vertical radiator one-half wavelength high if the operating
frequency is 1100 kHz?
a) 120 m
b) 136 m
c) 115 m
d) 124 m
27) Calculate the efficiency of an antenna that has a radiation resistance of 73 ohms and an
effective dissipation resistance of 5 ohms.
a) 98.3 %
b) 93.6 %
c) 90.7 %
d) 95.5 %
28) The line bisecting the major lobe, or pointing from the center of the antenna in the direction
of maximum radiation is called _____.
a) line of shoot
b) diagonal shoot
c) bisecting shoot
d) antenna shoot
29) The ammeter connected at the base of a Marconi antenna has a certain reading. If this reading
is increased 2.77 times, what is the increase in output power?
a) 3.45
b) 1.89
c) 2.35
d) 7.67
30) Refers to a field pattern that is close to the antenna
a) induction field
b) far field
c) radiation
d) capture field
31) A half-wave dipole is driven a 5-W signal at 225MHz. A receiving dipole 100 km. Calculate
the received power into a 73-ohm receiver.
a) 23.5 pW
b) 7.57 pW
c) 5.64 pW
d) 1.26 pW
32) It is the resistance that, if it replaced the antenna, would dissipate exactly the same amount of
power that the antenna radiates.
a) directivity gain
b) antenna efficiency
c) radiation resistance
d) antenna resistance
33) What is the effective radiated power of a television broadcast station if the output of the
transmitter is 1000W, antenna transmission line loss is 50W, and the antenna power gain is 3.
a) 1250 W
b) 2370 W
c) 2130 W
d) 2850 W
34) It is the ratio of the power radiated by an antenna to the sum of the power radiated and the
power dissipated.
a) radiation resistance
b) coupling resistance
c) antenna efficiency
d) antenna beamwidth
35) It is the ratio of the power radiated by the antenna to the total input power.
a) antenna efficiency
b) reflection coefficient
c) standing wave ratio
d) radiation resistance
36) If a 500-kHz transmitter of a constant power produces field strength of 100 V/m at a
distance of 100 mil from the transmitter, what would be the field strength at a distance of 200
mi from the transmitter?
a) 45V/m
b) 100 V/m
c) 50 V/m
d) 35 V/m
37) An antenna that transmits or receives equally well in all directions is said to be ______.
a) omnidirectional
b) bi-directional
c) unidirectional
d) quadsidirectional
38) It is the ratio of the power density radiated in a particular direction to the power density
radiated to the same point by a reference antenna, assuming both antennas are radiating the
same amount of power.
a) power gain
b) directive gain
c) total gain
d) system gain
39) If the field intensity of 25 mV/m develops 2.7 V in a certain antenna, what is its effective
height?
a) 110 m
b) 100 m
c) 98 m
d) 108 m
40) The magnetic field of an antenna is perpendicular to the earth. The antennas polarization
______.
a) is vertical
b) is horizontal
c) is circular
d) cannot be determined from the information given
41) If the power of a 500-kHz transmitter is increased from 150W to 300W, what would be the
percentage change in field intensity at a given distance from the transmitter?
a) 141 %
b) 150 %
c) 100 %
d) 133 %
42) It is the same with directive gain except that the total power fed to the antenna is used and the
antenna efficiency is taken into account.
a) system gain
b) power gain
c) directive gain
d) total gain
43) A ship-radio telephone transmitter operates on 2738 kHz. At a certain point distant from the
transmitter, the 2738-kHz signal is measured field at 147 mV/m, the second harmonic field at
the same decibels, how much has the harmonic emission been attenuated below the 2738-
kHz fundamental?
a) 43.2 dB
b) 51.2 dB
c) 35.1 dB
d) 25.1 dB
44) It is the equivalent power that an isotropic antenna would have to radiate to achieve the same
power density in the chosen direction at a given point as another antenna.
a) EIRP
b) ERP
c) IRL
d) RSL
46) For a transmitter antenna with a power gain of 10 and an input power of 100W, determine the
EIRP in watts.
a) 30 dBW
b) 40 dBW
c) 50 dBW
d) 20 dBW
47) If the energy is applied at the geometrical center of antenna, the antenna is said to be
________.
a) center-fed
b) end-fed
c) quarterwave-fed
d) halfwave-fed
48) For a transmit antenna with a power gain of 10 and an input power of 100W, determine the
power density at a point 10 km from the transmit antenna
a) 0.574 W/m2
b) 0.796 W/m2
c) 1.24 W/m2
d) 0.981 W/m2
49) For a transmit antenna with a radiation resistance of 72 ohms, an effective antenna resistance
of 8 ohms, a directive gain of 20 and an input power of 100W, determine the antenna
efficiency.
a) 90 %
b) 96 %
c) 98 %
d) 96 %
50) The field surrounding the antenna do not collapse their energy back into the antenna but
rather radiate it out into space.
a) induction field
b) near field
c) radiation field
d) magnetic field
51) For receive power density of 10W/m2 and a receive antenna with a capture area of 0.2 m2,
determine the captured power.
a) 0.5 W
b) 2 W
c) 1 W
d) 1.5 W
52) The property of interchangeability for the transmitting and receiving operations is known as
_____.
a) efficiency
b) accuracy
c) reciprocity
d) polarization
56) The angular separation between two half-power points in the major lobe of the antennas
plane radiation pattern.
a) bandwidth
b) polarization
c) efficiency
d) beamwidth
58) Defined as the frequency range over which antenna operation is satisfactory.
a) beamwidth
b) channel
c) bandwidth
d) baseband
60) The point on the antenna where the transmission line is connected is called _____.
a) center feed
b) end feed
c) feedpoint
d) voltage feed
63) The feedpoint presents and ac load to the transmission line called
a) antenna output impedance
b) antenna input impedance
c) feedpoint impedance
d) center feed impedance
70) Top loading is sometimes used with an antenna in order to increase its
a) effective height
b) bandwidth
c) beamwidth
d) input capacitance
72) The standard reference antenna for the directive gain is the _____.
a) infinitesimal dipole
b) isotropic antenna
c) elementary doublet
d) half-wave dipole
73) An antenna which is one-quarter wavelength long, mounted vertically with the lower end
either connected directly to ground or grounded through the antenna coupling network.
a) loop antenna
b) hertzian antenna
c) monopole antenna
d) turnstile antenna
76) Which of the following terms does not apply to the Yagi-Uda array
a) good bandwidth
b) parasitic elements
c) folded dipole
d) high gain
77) It effectively cancels out the capacitance component of the antenna input impedance.
a) ground plane
b) top hat
c) loading coil
d) shunt capacitance
78) Indicate which of the following reasons for the use of an earth mat with antennas is false:
a) impossibility of a good ground conduction
b) provision of an earth for the antenna
c) protection of personnel working underneath
d) improvement of the radiation pattern of the antenna
79) A metallic array that resembles a spoke wheel placed at the top of an antenna, it increases the
shunt capacitance to ground reducing the overall antenna capacitance.
a) loading coil
b) top loading
c) series capacitance
d) series inductors
81) It is formed when two or more antenna elements are combined to form a single antenna.
a) antenna elements
b) antenna arrays
c) driven elements
d) parasitic elements
82) One of the following is not a reason for the use of an antenna coupler:
a) to make the antenna look resistive
b) to provide the output amplifier with the correct load impedance
c) to discriminate against harmonics
d) to prevent reradiation of local oscillators
84) Indicate which of the following reasons for using counterpoise with antennas is false:
a) impossibility of a good ground connection
b) protection of personnel working underneath
c) provision of an earth for the antenna
d) rockiness of the ground itself
85) Type of antenna element that is directly connected to the transmission lines and receives from
or is driven by the source.
a) driven array
b) parasitic array
c) driven element
d) parasitic element
87) Type of antenna element that is not connected to the transmission lines.
a) parasitic array
b) driven array
c) parasitic array
d) parasitic element
88) One of the following is very useful as a multiband HF receiving antenna. This is the:
a) conical horn
b) folded dipole
c) log-periodic
d) square loop
89) A parasitic element that is longer than the driven element from which it receives energy.
a) driven element
b) director
c) parasitic element
d) reflector
91) A parasitic element that is shorter than its associated driven element.
a) redirector
b) director
c) reflector
d) parasitic element
93) It is a non resonant antenna capable of operating satisfactory over a relatively wide
bandwidth, making it ideally suited for HF transmission.
a) turnstile antenna
b) loop antenna
c) rhombic antenna
d) discone antenna
95) It is a linear array antenna consisting of a dipole and two or more parasitic elements: one
reflector and one director.
a) broadside antenna
b) end-fire antenna
c) yagi-uda antenna
d) phased array antenna
96) An antenna which is consists of a cone that is truncated in a piece of circular waveguide.
a) pyramidal horn antenna
b) circular horn antenna
c) rectangular horn antenna
d) conical horn antenna
98) An antenna formed by placing two dipoles at right angles to each other, 90 degrees out of
phase.
a) discone antenna
b) turnstile antenna
c) bicone antenna
d) 5/8 wavelength shaped
102) It is a ration of the highest to the lowest frequency over which n antenna will satisfactoru
operate.
a) channel ratio
b) bandwidth ratio
c) reflection ratio
d) dynamic range
103) An antenna has a power gain of 15. The power applied to the antenna is 32 W. The
effective radiated power is ______.
a) 15 W
b) 32 W
c) 120 W
d) 480 W
104) It is simply a single-turn coil of wire that is significantly shorter than one wavelength and
carries RF current.
a) turnstile antenna
b) loop antenna
c) rhombic antenna
d) long-wire antenna
105) A coax has an attenuation of 2.4 dB per 100 ft. The attenuation of 275 ft.
a) 2.4 dB
b) 3.3 dB
c) 4.8 dB
d) 6.6 dB
106) It is a group of antennas or group of antenna arrays that when connected together,
function as a simple whose beamwidth and direction can be changed electronically withour
having to physically move any of the individual antennas or antenna elements within the
array.
a) end fire antenna
b) broadside antenna
c) phased array antenna
d) log-periodic antenna
107) Conductors in multielement antennas that do not receive energy directly from the
transmission line are known as ______.
a) parasitic element
b) driven element
c) the boom
d) receptor
108) It is a broad VHF or UHF antenna that is suited for applications for which radiating
circular rather than horizontal or vertical polarized electromagnetic waved are required
a) discone antenna
b) bicone antenna
c) log-periodic antenna
d) helical antenna
110) Mode of propagation of helical antennas where radiation of the antenna in the axial
direction and produces a broadband relatively directional pattern
a) helical mode
b) normal mode
c) axial mode
d) helix mode
112) It is defined as the ratio of the antenna maximum gain in the forward direction to its
maximum gain in its backward direction.
a) side-to-back ratio
b) front-to-side ratio
c) back-to-side ratio
d) front-to-back ratio
114) An antenna that provides extremely high gain and directivity and very popular for
microwave radio and satellite communications link
a) helical antenna
b) parabolic antenna
c) hyperbolic antenna
d) log-periodic antenna
115) Part of a parabolic antenna that houses the primary antenna which radiates
electromagnetic waves toward the reflector.
a) feed mechanism
b) focal point
c) center feed
d) feed antenna
116) It is a passive device that simply reflects the energy radiated by the feed mechanism into
a concentrated, highly directional emission in which the individual waved are all in phase
with each other.
a) director
b) parabolic segment
c) reflector
d) feed mechanism
117) The energy near the edge of the parabolic dish that does not reflect but rather is diffracted
around the edge of the dish.
a) spillover
b) corona
c) dissipated power
d) copper loss
118) Determines the angular aperture of the reflector, which indirectly determines how much
the primary radiation is reflected by the parabolic dish.
a) numerical aperture
b) V number
c) aperture number
d) aperture angle
119) For a 2-m diameter parabolic reflector with 10W of power radiated by the feed
mechanism operating at 6 GHz with transmit antenna efficiency of 55 % and an aperture
efficiency of 55 % determine the beamwidth.
a) 1.25 degrees
b) 2.25 degrees
c) 1.5 degrees
d) 1.75 degrees
120) Type of lead mechanism where the primary radiating source is located just behind a small
opening at the vertex of the paraboloid rather than at the focus.
a) cassegrain feed
b) center feed
c) horn feed
d) antenna feed
121) Discone radiation pattern is
a) omnidirectional
b) unidirectional
c) figure of eight
d) bi-directional
124) At the ends of a half-wave antenna, what values of current and voltage exist compared to
the remainder of the antenna?
a) minimum voltage and maximum current
b) minimum voltage and minimum current
c) equal voltage and current
d) maximum voltage and minimum current
126) Consists of basic antenna connected to a transmission line plus one or more additional
conductors
a) parasitic array
b) directors
c) driven array
d) reflectors
133) How much move feed-point impedance does a folded-dipole have than normal dipole?
a) two times as much
b) three times as much
c) four times as much
d) five times as much
137) Why would the wires of V beam be closer together when used on higher frequencies?
a) main lobe lays further to wire
b) main lobe lays closer to wire
c) secondary lobes closer to wire
d) secondary lobes further to wire
141) In what direction is the null of small diameter loop in relation to the plane of the loop?
a) 45 degrees angle
b) 180 degrees angle
c) 360 degrees angle
d) 90 degrees angle
142) When is a loop unidirectional?
a) when horizontal
b) when vertical
c) when circular
d) when unidirectional
145) Why might L networks be used between an antenna and transmission line?
a) step impedance up
b) step impedance down
c) better radiation of energy
d) reduce power radiation
146) Why are antenna ammeters often shorted out or disconnected from the antenna expect
when readings are desired?
a) to replace it with dummy
b) not to interfere with transmission
c) for proper reception of signals
d) to protect from lightning
147) Device to split transmission line current to two or more antenna towers
a) splitter
b) coupler
c) isolator
d) phasor circuit
148) What method can be used to determine the feed-point impedance of a vertical antenna?
a) resistance substitution
b) impedance matching
c) dissipated resistance measurement
d) grounding the antenna
151) Under what condition might a harmonic of a transmission be heard at a distant point
when the fundamental cannot be?
a) when the carrier is weak
b) when fundamental is too weak
c) when harmonics are weak
d) when the harmonics are amplified
155) What feed requirements must be met to produce a circular radiation pattern when using
two crossed dipoles?
a) feed 180degrees apart electrically
b) feed 45 degrees apart electrically
c) feed 360 degrees apart electrically
d) feed 90 degrees apart electrically
157) In what range of frequencies are most omnidirectional horizontally polarized antennas
used?
a) VHF and UHF
b) HF and VHF
c) UHF and HF
d) LF and MF
MULTIPLE CHOICE QUESTIONS IN
MICROWAVE
COMMUNICATIONS
Electronics Systems and Technologies
By
Melvin C. Arceo
ENCODED BY:
LORENZO, Luer Breech B.
1) IF repeaters are also called
a) heterodyne receiver
b) mixer/receiver
c) radio receiver
d) FM receiver
2) It is the difference between the nominal output power of a transmitter and the minimum input
power required by a receiver
a) RSL
b) IRL
c) system gain
d) FSL
4) A ferrite is
a) a nonconductor with magnetic properties
b) an intermetallic compound with particularly good conductivity
c) an insulator which heavily attenuates magnetic fields
d) a microwave semiconductor invented by Faraday
11) Indicate which is not true. Compared with other types of radar, phased array radar has the
following advantages
a) very fast scanning
b) ability to track and scan simultaneously
c) circuit simplicity
d) ability to track many targets simultaneously
12) Given the frequency and dimensions of 5 GHz and 7 cm by 9 cm respectively, the beam of
the pyramidal horn is about ______.
a) 27 degrees
b) 53 degrees
c) 60 degrees
d) 80 degrees
13) The diameter of a parabolic reflector should be at least how many wavelengths at the
operating frequency?
a) 1
b) 2
c) 5
d) 10
16) Indicate which one of the following applications or advantages of radar beacons is false:
a) target identification
b) navigation
c) very significant extension of the maximum range
d) more accurate tracking enemy targets
17) Refers to more than one transmission path or method of transmission available between
transmitter and a receiver.
a) diversity
b) polarization
c) efficiency
d) accuracy
19) A direct path that exist between the transmit and receive antennas
a) LOS
b) direct waves
c) space waves
d) terrestrial waves
23) Which type of diode does not ordinarily operate with reverse bias?
a) Varactor
b) IMPATT
c) Snapp-off
d) Tunnel
25) A pyramidal horn used at 5 GHz has an aperture that is 7 cm by 9 cm. The gain is about
a) 10.5 dB
b) 11.1 dB
c) 22.6 dB
d) 35.8 dB
26) Type of diversity where the output of the transmitter is fed to two or more antennas that are
physically separated by an appreciable wavelengths
a) quad diversity
b) wavelength diversity
c) space diversity
d) hybrid diversity
28) A type of diversity where a single RF carrier is propagated with two different
electromagnetic polarization.
a) space diversity
b) wavelength diversity
c) polarization diversity
d) hybrid diversity
31) Type of diversity which consists of a standard frequency diversity path where the two
transmitter/receiver pair at one end of the path are separated from each other and connected
to different antennas that are vertically separated as in space diversity
a) quad diversity
b) wavelength diversity
c) space diversity
d) hybrid diversity
33) The combination of the frequency, space, polarization and receiver diversity into one system
a) hybrid diversity
b) quad diversity
c) space diversity
d) wavelength diversity
34) If the target cross section is changing, the best system for accurate tracking in
a) lobe switching
b) sequential lobing
c) conical switching
d) monopulse
35) The multicavity klystron
a) is not good low-level amplifier because of noise
b) has a high repeller voltage to ensure a rapid transmit time
c) is not suitable for pulse operation
d) needs a long transmit time through the buncher cavity to ensure current modulation
36) An arrangement that avoids a service interruption during periods of deep fades or equipment
failures.
a) service switching arrangement
b) protection switching arrangement
c) interruption switching arrangement
d) equipment switching arrangement
37) A type of attenuator where attenuation is accomplished by insertion of a thin card of resistive
material through a slot in the top of a waveguide
a) flap attenuator
b) vane attenuator
c) slot attenuator
d) directional coupler
38) After a target has been acquired, the best scanning system for tracking is
a) nodding
b) spiral
c) conical
d) helical
40) Type of protection switching arrangement where each working radio channel has a dedicated
backup or spare channel
a) hot swap
b) hot backup
c) hot standby
d) hot diversity
43) A half wavelength, closed section of a waveguide that acts as a parallel resonant circuit is
known as _____.
a) half-wave section
b) cavity resonator
c) LCR circuit
d) directional couple
46) Which of the following devices are not being used in microwave power amplifier?
a) klystron tubes
b) traveling wave tubes
c) IMPATT
d) magnetron
48) It is a unidirectional device often made up of ferrite material used in conjunction with a
channel-combining network to prevent the output from interfering with the output of another
transmitter
a) circulator
b) magic tee
c) isolator
d) rat race
49) Which is not true about the following: Flat-topped rectangular pulses must be transmitted in
radar to
a) allow a good minimum range
b) make the returned echoes easier to distinguish from the noise
c) prevent frequency changes in the magnetron
d) allow accurate range measurements
50) The power that leaks out of the back and sides of the transmit antenna interfering with the
signal entering with the signal entering the input of a nearby receive antenna.
a) ringaround
b) ringabout
c) roundabout
d) turnaround
51) Which of the following is not true: The radar cross section of a target
a) depends on the frequency used
b) may be reduced by special coating of the target
c) depends on the aspect of a target, if this nonspherical
d) is equal to the actual cross-sectional area for small targets
52) It is a general term applied to the reduction in signal strength at the input to a receiver
a) fading
b) attenuation
c) absorption
d) ghosting
53) Indicate which of the following cannot be followed by the word waveguide
a) elliptical
b) flexible
c) coaxial
d) ridged
54) If the ratio of the antenna diameter to the wavelength in a radar system is high, this will result
in (indicate the false statement)
a) large maximum range
b) good target discrimination
c) difficult target acquisition
d) increased capture area
57) Applies to propagation variables in the physical radio path which affect changes in path loss
between the transmitter at one station and its normal receiver at the other station.
a) ghosting
b) absorption
c) attenuation
d) fading
58) If the antenna diameter in a radar system is increased by a factor of 4, the maximum range
will be increased by a factor of
a) square root of 2
b) 2
c) 4
d) 8
59) If the peak transmitted power in a radar system is increased by a factor of 15, the maximum
range will be increased by a factor of
a) 2
b) 4
c) 8
d) 16
60) Varactor and step-recovery diodes are widely used in what type of circuit?
a) amplifier
b) oscillator
c) frequency multiplier
d) mixer
64) It is the ratio of the wideband carrier to the wideband noise power
a) carrier to noise ratio
b) signal to noise ratio
c) energy per bit per noise density ratio
d) noise figure
65) What is the duty cycle of a radar pulse if the pulse width is 1s, the pulse repetition rate is
900, and the average power is 18 W?
a) 0.09 %
b) 0.99 %
c) 0.90 %
d) 1.00 %
66) A microwave tube amplifier uses an axial magnetic field and a radial electric field. This is the
a) reflex klystron
b) coaxial magnetron
c) traveling-wave magnetron
d) CFA
67) Figure of merit used to indicate how much the signal-to-noise ratio deteriorates as a signal
passes through a circuit or series of circuits
a) noise factor
b) signal to noise ratio
c) carrier to noise ratio
d) dynamic range
68) What is the peak power of a radar pulse if the pulse width is 1s, the pulse repetition rate is
900, and the average power is 18 W?
a) 10 kW
b) 15 kW
c) 20 kW
d) 30 kW
69) The point where the antenna is mounted with respect to the parabolic reflector is called the
a) focal point
b) center
c) locus
d) tangent
70) The operating frequency of klystron and magnetrons is set by the
a) cavity resonators
b) DC supply voltage
c) inputsignal frequency
d) Number of cavities
71) Using a small reflector to beam waves to the larger parabolic reflector is known as
a) focal feed
b) horn feed
c) cassegrain feed
d) coax feed
72) If the noise figures and gains of each of the amplifiers in cascade is 3 dB and 10 dB
respectively. What is the total noise figure?
a) 2.12 dB
b) 3.24 dB
c) 1.24 dB
d) 4.23 dB
74) Calculate the maximum ambiguous range for a radar system with PRT equal to 400s.
a) 13.8 mi
b) 43.5 mi
c) 16.4 mi
d) 32.8 mi
76) What is the distance in nautical miles to a target if it takes 123 s for a radar pulse to travel
from the radar antenna to the target, back to the antenna, and be displayed on the PPI scope?
a) 10 nmi
b) 5 nmi
c) 20 nmi
d) 15 nmi
78) Calculate the coupling of a directional coupler that has 70 mW into the main guide and 0.35
mW out the secondary guide.
a) 13 dB
b) 23 dB
c) 33 dB
d) 10 dB
81) The main difference between the operation of transmission liners and waveguides is that
a) the latter is not distributed, like transmission lines
b) the former can use stubs and quarter-wave transformers, unlike the latter
c) transmission lines use the principal mode of propagation, and therefore do not
suffer from low-frequency cut-off
d) terms such as impedance matching and standing-wave ratio cannot be applied to
waveguides
82) The useful power of the transmitter that is contained in the radiated pulses is termed as
______.
a) rms power
b) rated power
c) peak power
d) average power
83) In radars, echoes that are produced when the reflected beam is strong enough to make a
second trip
a) double range echoes
b) double frequencies echoes
c) second return echoes
d) second time around echoes
84) Indicate the false statement. Compared with equivalent transmission lines, 3 GHz
waveguides
a) are less lossy
b) can carry higher powers
c) are less bulky
d) have lower attenuation
85) The range beyond which targets appear as second return echoes is called
a) maximum range
b) maximum unambiguous range
c) maximum usable range
d) any of these
86) When a particular mode is excited in a waveguide, there appears an extra electric component,
in the direction of propagation. The resulting mode is
a) transverse electric
b) transverse magnetic
c) longitudinal
d) transverse-electromagnetic
87) In radars, echoes that arrive after the transmission of the next pulse are called _____.
a) second return echoes
b) second time around echoes
c) multiple time around echoes
d) any of these
88) When electromagnetic waves are reflected at an angle from a wall, their wavelength along
the wall is
a) the same as the free space
b) the same as the wavelength perpendicular to the wall
c) shortened because of the Doppler effect
d) greater than in the actual direction of propagation
90) As a result of reflections from a plane conducting wall, electromagnetic waves acquire an
apparent velocity of light in space
a) velocity of propagation
b) normal velocity
c) group velocity
d) phase velocity
91) In radars, the time between pulses is called ______.
a) rest time
b) duration time
c) delay time
d) propagation time
92) Indicate the false statement. When the free-space wavelength of a signal equals the cutoff
wavelength of the guide
a) the group velocity of the signal becomes zero
b) the phase velocity of the signal becomes infinite
c) the characteristic impedance of the guide becomes infinite
d) the wavelength within the waveguide becomes infinite
94) A signal propagated in a waveguide has a full wave electric intensity change between two
further walls, and no component of the electric field in the direction of propagation. The
mode is
a) TE11
b) TE10
c) TM22
d) TE20
95) In radars, the number of the pulses transmitted per second is called
a) pulse repetition frequency
b) pulse repetition time
c) pulse repetition phase
d) pulse number of repetition
96) Which of the following is incorrect? The dominant mode of propagation is preferred with
rectangular waveguides because
a) it leads to the smallest waveguide dimensions
b) the resulting impedance can be matched directly to coaxial lines
c) it is easier to excite than other modes
d) propagation of it without any spurious generation can be ensured
97) It is a mean of employing radio waves to detect and locate objects such as aircraft, ships and
land masses.
a) detectors
b) radars
c) repeaters
d) beacons
99) The resonant frequency of a cavity may be varied by changing any of these parameters
except:
a) cavity volume
b) cavity inductance
c) cavity capacitance
d) cavity resistance
100) In order to couple two generators to a waveguide system without coupling them to each
other, which could not be use?
a) rat-race
b) E-plane T
c) hybrid ring
d) magic T
101) A type of tee so-named because of the side arms shunting the E field for the TE modes,
which is analogous to voltage in the transmission lines
a) magic tee
b) rat tee
c) series tee
d) shunt tee
102) Which one of the following waveguide tuning components is not easily adjustable?
a) screw
b) stub
c) iris
d) plunger
106) Cylindrical cavity resonators are not used with klystron because they have
a) a Q that is too low
b) a shape whose resonant frequency is too difficult to calculate
c) harmonically related resonant frequencies
d) too heavy losses
107) In waveguides, if no component of the E field is in the direction of propagation the mode
is said to be
a) TE
b) TM
c) TEM
d) TME
108) A directional coupler with three or more holes is sometimes used in preference to the
two-hole coupler
a) because it is more efficient
b) to increase coupling of the signal
c) to reduce spurious mode generation
d) to increase the bandwidth of the system
109) The smallest free-space wavelength that is just unable to propagate in the waveguide
a) cutoff wavelength
b) cutoff frequency
c) cutoff waveguide length
d) cutoff phase
110) It is the minimum frequency of waves that can propagate through the waveguide
a) cutoff frequency
b) cutoff wavelength
c) cutoff phase
d) cutoff waveguide length
113) The maximum power that may be handled by a ferrite component is limited by the
a) curie temperature
b) saturation magnetization
c) line width
d) gyromagnetic resonance
118) For some applications, circular waveguides may be preferred to rectangular ones because
of
a) the smaller the cross section needed at any frequency
b) lower attenuation
c) freedom from spurious modes
d) rotation of polarization
120) In a klystron amplifier, velocity modulation of the electron beam is produced by the
a) collector
b) catcher cavity
c) cathode
d) buncher cavity
121) Increasing the diameter of a parabolic reflector causes which of the following:
a) decreased beamwidth
b) increased gain
c) none of the above
d) decreased beamwidth and increased gain
124) One of the reasons why vacuum tubes eventually fail at microwave frequencies is that
their
a) noise figure increases
b) transmit time becomes too short
c) shunt capacitive reactances becomes too large
d) series inductance reactances becomes too small
125) A rectangular waveguide has a width of 1 inch and a height of 0.6 inch. Its cutoff
frequency is
a) 2.54 GHz
b) 3.0 GHz
c) 5.9 GHz
d) 11.8 GHz
126) The TWT is sometimes preferred to the multicavity klystron amplifier, because the
former
a) is more efficient
b) has a greater bandwidth
c) has a higher number of modes
d) produces higher output power
140) Indicate the false statement. Transit time in microwave tubes will be reduced if
a) the electrodes are brought closer together
b) a higher node current is used
c) multiple or coaxial loads are used
d) the anode voltage is made larger
141) Coaxial cable is not widely used for long microwave transmission lines because of its
a) high loss
b) high lost
c) large size
d) excessive radiation
142) The main advantage of the TWT over a klystron for microwave amplification is
a) lower cost
b) smaller size
c) higher power
d) wider bandwidth
144) A waveguide has a cutoff frequency of 17 GHz. Which of the signals will not be passed
by the waveguide?
a) 15 GHz
b) 18 GHz
c) 22 GHz
d) 25 GHz
145) When the electric field in a waveguide is perpendicular to the direction of wave
propagation, the mode is said to be
a) vertical polarization
b) transverse electric
c) horizontal polarization
d) transverse magnetic
146) The TWT is sometimes preferred to the magnetron as a radar transmitter output tube
because it is
a) capable of longer duty cycle
b) a more efficient amplifier
c) more broadband
d) less noisy
150) Indicate the false statement. Klystron amplifiers may use intermediate cavities to
a) prevent oscillations that occur in two-cavity klystron
b) increase the bandwidth of the device
c) improve the power gain
d) increase the efficiency of the klystron
152) The following transmission lines are used for microwave frequencies, except:
a) waveguide
b) twin lead
c) coax
d) stripline
158) What is the name of the microwave transmission line that is used in printed circuits?
a) microstrip
b) coax
c) twin lead
d) twisted pair
163) What type of coupling is used between a waveguide and a waveguide wavemeter?
a) loop antenna
b) quarterwave antenna
c) hole
d) E probe
169) Which vacuum tube do you think oscillate at the highest frequency
a) Magnetron
b) Gunn
c) Klystron
d) BWO
182) What is the advantage of using a circulator with two transmitter and two receivers?
a) many antennas
b) less interference
c) easy coupling
d) one antenna only
183) To what must the fourth port be connected in a tunnel diode amplifier?
a) resistor
b) inductor
c) capacitor
d) impedance
189) To what two circuits would a radar timer circuit feed signals?
a) modulator and mixer
b) amplifier and circulator
c) modulator and circulator
d) amplifier and modulator
197) What other circuit might be used as an oscillator that determines the PRR?
a) trapezoidal generator
b) unbalanced multivibrator
c) bistablemultivibrator
d) sinewave generator
201) What is used to carry RF energy from magnetron to antenna in a radar set?
a) helix
b) parallel wireline
c) coax
d) waveguide
206) In radar, if the mixer diode burns out, what are replaced?
a) tube
b) mixer
c) antenna
d) diode
207) What is the cavity between magnetron and mixer cavity called?
a) ATR
b) TR
c) Transmit
d) Receive
213) Sea return is the control that desentisizes a radar receiver for _____
a) 5 10 microseconds
b) 15 20 microseconds
c) 10 15 microseconds
d) 20 25 microseconds
218) If echo signals are developed as negative pulses, to what part of the CRT would they be
fed in radar?
a) anode
b) grid
c) cathode
d) 2nd grid
220) Why is a selsyn pair not too successful for radar antenna synchronization?
a) constant lead angle
b) variable lag angle
c) constant lag angle
d) variable lead angle
224) What is used to indicate the bow of the ship on the CRT?
a) tail flash
b) body flash
c) heading flash
d) none
226) What qualification must a person have before he is eligible to make repairs to a radar set?
a) NTC endorsement
b) repair license
c) repair endorsement
d) radar endorsement
230) Why are signal nulls used in Radio Direction Finders work?
a) sharper than maximums
b) sharper than minimums
c) duller than maximums
d) duller than minimums
231) How many are signal nulls in one loop rotation Radio Direction Finders?
a) 3
b) 4
c) 5
d) 2
232) Under what conditions do the horizontal portions of a loop pick up difference currents in
RDF?
a) ground waves
b) sky waves
c) space waves
d) direct waves
234) For what are unidirectional readings used in loops for RDF?
a) resolve a 180 degrees ambiguity
b) resolve a 90 degrees ambiguity
c) resolve a 360 degrees ambiguity
d) resolve a 270 degrees ambiguity
236) In RDF, what happens to a radio wave path as it moves outward across a coastline as less
than 90 degrees?
a) bends away from the shore
b) travels along the shore
c) bends towards shore
d) travels across the shore
240) At what time of the day is direction finder bearings least accurate
a) sunset
b) sunrise
c) mid-day
d) sunset and sunrise
243) How is it that none of the 120-550 kHz ADF circuits are tuned to the desired station?
a) narrowband amplifiers
b) broadband amplifiers
c) IF amplifiers
d) Mixers
245) What forms the error signal that actuates the ADF servo-motor?
a) 75-Hz carrier
b) 114-Hz carrier
c) 114-Hz sideband
d) 75-Hz sideband
249) If two bearing are determined from a radio beacon or station over a period of a few
minutes, what else must be known to determine the ships position?
a) speed
b) elapses time
c) ships course
d) any of these
TELEPHONY AND
FACSIMILE
Electronics Systems and Technologies
By
Melvin C. Arceo
ENCODED BY:
RIVERA, Billy Joe S.
1. The simplest and most straightforward form of telephone service is called
2. _______ are local telephone switches equipped with SS7-compatible software and terminating
signal links
A. switching points
B. service points
C. point codes
D. service switching points
3. A PABX is normally connected to the central office via an interface device called
A. group 1
B. group 2
C. group 3
D. group 4
6. Signals that provides call status information, such as busy or ringback signals
A. supervising
B. hybriding
C. controlling
D. ringing
7. A signal sent back to the calling party at the same time the ringing signal is sent to the called
party
A. busy signal
B. ringing signal
C. ringback signal
D. dial tone
A. telephone line
B. telephone set
C. telephone circuit
D. telephone trunk
9. The drum diameter of a facsimile machine is 90.2 mm and the scanning pitch is 0.2 mm per
scan. Find the index of cooperation according to CCITT
A. 451
B. 2.22 x 10^-3
C. 1417
D. 144
10. It is the ratio in dB of the power of a signal at that point to the power the same signal would
be 0-dBm at any point in the transmission system
A. data level
B. baseband level
C. voice level
D. transmission level
11. It is an indirect method of evaluating the phase delay characteristics of the circuit
A. crosstalk
B. interference
C. impulse noise
D. drop out
13. It is the presence of one or more continuous, unwanted tones within the message channels,
the tones are often caused by crosstalk or cross modulation between adjacent channels in a
transmission system due to system nonlinearities.
A. multiple-frequency interference
B. single-frequency interference
C. co-channel interference
D. desensitizing
14. That portion of the local loop that is strung between the poles
A. aerial
B. distribution cable
C. feeder cable
D. twisted-pair
15. It is the primary cause of attenuation and phase distortion on a telephone circuit
A. local line
B. local loop
C. subscriber loop
D. any of these
16. It is simply the frequency response of a transmission medium referenced to a 1004-Hz test
tone
A. attenuation distortion
B. differential gain
C. 1004-Hz deviation
D. any of these
17. The time delay measured in angular units, such as degrees or radians is called __________
A. propagation time
B. phase delay
C. holding time
D. system delay time
18. It is a communications term that indicates the presence of a signal power comparable to the
power of an actual message transmission
A. dynamic range
B. loaded
C. node
D. reference
19. It is any device used to originate and terminate calls and to transmit and receive signals into
and out of the telephone network
A. instrument
B. station equipment
C. station
D. any of these
20. Exchanges connected directly to the local loops are called ______________
A. central office
B. local exchange
C. exchange offices
D. any of these
21. It provides functionality of communicating with the voice switch by creating the packets or
signal units necessary for transmission over the SS7 network
A. switching points
B. service points
C. point codes
D. service switching points
22. In a 4-wire telephone set connection, (used to connect telephone set to central office
switching) the green coded wire is used _______________
A. as ground wire
B. to transmit the signal
C. to receive the signal from the far end
D. as a spare or for special purpose applications
23. A technique where the called subscriber is served by any other central office, the switching
equipment will have to transfer the digit dialed to the called switching equipment.
A. loop signaling
B. step-by-step switching
C. interoffice calling
D. duplex signaling
A. coupling crosstalk
B. transmission crosstalk
C. linear crosstalk
D. non-linear crosstalk
25. The number of dedicated lines used to interconnect 100 parties
A. 99 lines
B. 1250 lines
C. 4950 lines
D. 3450 lines
26. Class of switching office which is the local exchange where the subscriber loops terminated
and received dial tone.
A. Class 5
B. Class 4C
C. Class 3
D. Class 1
A. on-hook
B. off-hook
C. semi-hook
D. hook-in
29. Type of loop signaling which is widely used in new switching systems to supervise trunks
between two central offices.
30. Printed documents to be transmitted by fax are converted into a baseband electrical signal by
the process of
A. reflection
B. scanning
C. modulation
D. light variations
32. It is a distortion formed if SSB is used where the information bandwidth is greater than half
of the carrier frequency.
A. near-far effect
B. hauffman effect
C. kendall effect
D. herringbone effect
33. It is simply an unshielded twisted pair transmission line consisting of two insulated
conductors twisted together.
A. local loop
B. local line
C. subscriber loop
D. any of these
34. It is an audible signal comprised of two frequencies: 350 Hz and 440 Hz
A. dial tone
B. ringback signal
C. busy tone
D. call waiting tone
35. It enables the destination station of a telephone call to display the name of the telephone
number of the calling party before the telephone is answered.
A. conference call
B. call wait
C. call forwarding
D. caller id
36. The largest cable used in a local loop, usually 3600 pair of copper wires placed underground
or in conduit.
A. feeder cable
B. distribution cable
C. drop wire
D. drop-wire cross-connect cables
37. A weighting technique that assumes a perfect receiver only, therefore its weighting curve
corresponds to the frequency response of the ear only.
A. relative noise weighting
B. above relative noise weighting
C. C-message noise weighting
D. psophometric noise weighting
39. A special type of line conditioning that sets the minimum requirements for signal-to-noise
ratio a nonlinear distortion.
A. crosstalk
B. co-channel interference
C. phase jitter
D. spikes
A. linear crosstalk
B. transmittance crosstalk
C. nonlinear crosstalk
D. coupling crosstalk
A. subscriber
B. destination
C. source
D. terminal
43. It is a system of sensors, switches and other electronic and electrical devices that allow
subscriber to give instructions directly to the switch without having to go through the operator.
44. Toll offices are connected to other toll offices with _____________
A. intertoll trunks
B. intratoll trunks
C. interoffice trunks
D. intraoffice trunks
45. The highest ranking office in the DDD network in term of size of the geographical area
served and the trunk options available.
A. End office
B. Sectional center
C. Regional center
D. Toll center
46. He invented the automatic line selector, which led to the automatic telephone system.
A. Alexander Bain
B. Alexander Graham Bell
C. Thomas Edison
D. Almon Strowger
47. It allows customers to change to a different service and still keep the same phone number
A. changing
B. porting
C. transporting
D. portability
A. 1.8 dB
B. 4 dB
C. 1.4 dB
D. 3 dB
49. When the telephone set is in the ____________ state, a direct current from the central office
(CO) flows through the transmitter and receiver of the handset.
A. on-hook
B. off-hook
C. semi-hook
D. hook-in
50. Type of loop signaling which involves opening and closing the loop to dial to or through the
central office.
51. When the image at the receiving end of a facsimile transmission is elongated vertically,
A. fidelity
B. contrast
C. legibility
D. chroma
54. The feedback signals that help prevent the speaker from talking too loudly.
A. busy tone
B. ringback tone
C. dial tone
D. sidetone
A. loop signaling
B. station signaling
C. interoffice signaling
D. pulse signaling
56. A signal sent from the switching machine back to the calling station whenever the system
cannot complete call because of equipment unavailability.
A. busy tone
B. call waiting tone
C. fax tone
D. congestion tone
57. The final length of cable pair that terminates at the SNI
A. aerial
B. drop wire
C. distribution cable
D. cross-connect cables
58. It is the difference in circuit gain experienced at a particular frequency with respect to the
circuit gain of a reference frequency.
A. dynamic range
B. absorption distortion
C. attenuation distortion
D. selective fading
59. In telephone systems, a special type of line conditioning that pertains to line impairments for
which compensation can be made with filters and equalizers.
A. A-line conditioning
B. B-line conditioning
C. C-line conditioning
D. D-line conditioning
60. An envelope delay distortion test on a basic telephone channel indicated that an 1800-Hz
carrier experienced the minimum absolute delay of 400 us. The maximum envelope delay for a
basic telephone channel is 1750 us within the frequency range 800 Hz to 2600 Hz. What is the
maximum envelope delay?
A. 2150 microsec
B. 2550 microsec
C. 3000 microsec
D. 3400 microsec
61. In SS7 signaling points, codes that are carried in signaling messages exchanged between
signaling points to identify the source and destination of each message
A. signaling points
B. service points
C. switching points
D. point codes
62. Stage of the step-by-step switching system that is composed of switches to complete the
connection to the called subscriber.
A. line equipment
B. switch train
C. connectors
D. switching network
63. ____________ is the switching system that is a branch of the local central office.
A. local exchange
B. branch exchange
C. subscriber loop
D. line
65. Aside from tip and ring used in local loops the third wire when used is called __________.
A. reserve
B. sleeve
C. ground
D. none of these
66. Acknowledgement and status signals that ensure the process necessary to set up and
terminate a telephone call are completed in an orderly and timely manner,
69. In telephone systems, a special type of line conditioning that specifies the maximum limit for
attenuation distortion and envelope delay distortion.
A. A-line conditioning
B. B-line conditioning
C. C-line conditioning
D. D-line conditioning
70. A the receiver, the phase difference at the different carrier frequencies is called _________.
71. It is a sudden, random changes in the phase of the signal. They are classified as temporary
variations in the phase of the signal lasting longer than 4 ms.
A. phase hits
B. phase jitter
C. interference
D. distortion
72. Circuits that are designed and configured for their use only and often referred to as private
circuits or dedicated circuits.
A. switched circuits
B. leased circuits
C. virtual circuits
D. switched virtual circuits
A. circuit switch
B. tap switch
C. equipment switch
D. cross switch
74. Interstate long distance telephone calls require a small telephone office called _________.
A. sectional office
B. regional office
C. toll office
D. end office
75. A call that cannot be completed because the necessary trunk circuits or switching paths are
not available.
A. blocking
B. holding
C. storing
D. none of these
76. A mandate that requires all telephone companies to support the porting of telephone number.
A. subscriber loop
B. relay circuits
C. line sensors
D. supervisory relay
A. television
B. telecommunication
C. facsimile transmission
D. mobile communication
A. Newspaper text
B. Architectural drawings
C. Cable movies
D. Satellite weather photos
A. telephone
B. television
C. facsimile
D. computer
A. pulse modulation
B. amplitude modulation
C. phase modulation
D. frequency modulation
82. A device that serves as a demarcation point between local telephone company responsibility
and subscriber responsibility for telephone service.
84. It is a sudden, random change in the gain of the circuit resulting in a temporary change in the
signal level.
A. spikes
B. gain hits
C. jitter
D. echo
85. A typical echo suppressor suppresses the returned echo by how much?
A. 10 dB
B. 30 dB
C. 45 dB
D. 60 dB
86. In telephony, functions that supply and interpret control and supervisory signals needed to
perform the operation
A. calling functions
B. maintenance functions
C. signaling functions
D. transmission functions
A. central offices
B. exchange offices
C. exchanges
D. any of these
88. It is simply a path between two subscribers and is comprised of one or more switches, two
local loops or possibly one or more trunk circuits.
A. way
B. route
C. path
D. mode
89. It defines the procedures and protocols necessary to exchange information over the PSTN
using a separate digital signaling network to provide wireless and wireline telephone call setup,
routing and control.
A. any of these
B. common channel signaling system no. 7
C. SS7
D. C7
90. In a 4-wire telephone set connection, (used to connect telephone set to central office
switching) the red coded wire is used __________.
A. as ground wire
B. to transmit the signal
C. to receive the signal from the far end
D. as a spare or for special purpose applications
A. line
B. trunk
C. loop
D. signaling
93. It is a combination of passive components that are used to regulate the amplitude and
frequency response of the voice signals.
A. equalizer circuit
B. balanced transformer
C. balanced modulator
D. hybrid network
94. A signal that is sent from the switching machine back to the calling station whenever the
called telephone number is off-hook.
A. aerial
B. drop wire
C. feeder cable
D. distribution cable
96. It is a parameter equivalent to TLP except that it is used as a reference for data transmission.
97. He developed the first instrument that transmitted music over a wire
A. Philipp Reis
B. Antonio Meucci
C. Thomas Edison
D. Almon Strowger
98. It is used to convert two-wire circuits to four-wire circuits which is similar to hybrid coil
found in standard telephone sets.
A. balanced transformer
B. hybrid circuits
C. balanced modulator
D. hybrid transformers
99. A switchboard with four digits can accommodate how many telephone numbers?
A. 1,000
B. 10,000
C. 100,000
D. 9999
100. The trunk circuits that are terminated in tandem switches are called
A. tie trunks
B. tandem trunks
C. office trunks
D. exchange trunks
101. The class of switching office that provides service to small groups of class 4 offices within a
small area of state.
A. Class 1
B. Class 4
C. Class 2
D. Class 3
A. interoffice link
B. trunk
C. interoffice calling
D. loop
104. In telephony, the -48V dc voltage was used rather than ac voltages because
A. dial tone
B. signaling
C. supervising
D. alerting
106. Occurs in coherent SSBSC systems, such as those using frequency division multiplexing
when the received carrier is not reinserted with the exact phase relationship to the received signal
as the transmit carrier possessed.
107. It is simply the dedicated cable facility used to connect an instrument at a subscribers
station to the closest telephone office.
A. subscriber lines
B. local loops
C. subscriber loops
D. any of these
A. intraoffice call
B. intraexchange call
C. intraswitch call
D. any of these
109. Type of Class 4 toll center usually had only outward operator service or perhaps no operator
service at all.
A. Class 2
B. Class 4P
C. Class 1
D. Class 3
110. In a 4-wire telephone set connection, (used to connect telephone set to office central
switching) the yellow coded wire is used _______________.
A. as ground wire
B. to transmit the signal
C. to receive the signal from the far end
D. as a spare or for special purpose applications
111. When the image at the receiving end of a facsimile transmission us elongated horizontally,
112. It is a special balanced transformer used to convert a two-wire circuit into a four-wire circuit
and vice-versa.
A. equalizer circuit
B. balanced transformer
C. balanced modulator
D. hybrid network
113. It is a method originally used to transfer digits in the telephone set to the local switch.
A. tone dialing
B. dial pulsing
C. battery and ground pulsing
D. reverse battery pulsing
A. impulse noise
B. crosstalk
C. gain hits
D. interference
116. It eliminates the echo by electrically subtracting it from the original signal rather than
disabling the amplifier in the return circuit.
A. echo suppressors
B. echo limiters
C. echo cancellers
D. any of these
117. In telephony, functions that involve the actual transmission of a subscribers messages and
any necessary control signals.
A. transmission functions
B. signaling functions
C. maintenance functions
D. calling functions
118. The first computer-controlled central office switching system used in PSTN
A. No.7 ESS
B. No.2 ESS
C. No.5 ESS
D. No. 1 ESS
A. double office
B. tandem office
C. exchange office
D. local office
120. The 5-class switching hierarchy is a __________ scheme that establishes an end-to-end
route mainly through trial and error.
A. interleaved switching
B. progressive switching
C. point-to-point switching
D. step-by-step switching
A. manual switching
B. step-by-step
C. common control
D. Electronic
A. QAM
B. FSK
C. Vestigial sideband AM
D. FM
124. Signals that provides information in the form of announcements, such as number changed to
another number, a number no longer in service, and so on
A. addressing
B. ringing
C. controlling
D. supervising
125. The switch closure in an off-hook condition causes a range of dc current to flow on the
loop, what is that range of current?
A. 23 mA to 50 mA
B. 15 mA to 30 mA
C. 10 mA to 20 mA
D. 20 mA to 80 mA
126. These are unused sections of cables that are connected in shunt working cable pair, such as
a local loop. They are used for party lines to connect to the same local loop.
A. cross-connect loop
B. drop wire tap
C. bridge tap
D. wire tap
127. The time delay encountered by a signal as it propagates from a source to a destination is
called ____________.
A. propagation time
B. phase delay
C. holding time
D. system delay time
128. It is the decrease in gain of more than 12 dB lasting longer than 4 ms and is a characteristics
of temporary open circuit conditions and are generally caused by deep fades in radio facilities or
by switching delays.
A. echo
B. jitter
C. gain hits
D. dropouts
129. It is similar to the local loop except that it is used to interconnect two telephone offices.
A. trunk lines
B. subscriber loop
C. local lines
D. subscriber lines
130. Calls that are placed between two stations that are connected to different local exchanges.
A. interoffice calls
B. interswitch calls
C. interexchange calls
D. any of these
131. _________ is defined as a momentary on-hook condition that causes loop making and
breaking from the telephone set dialer toward the central office.
A. dial tone
B. dial pulsing
C. on-hook
D. off-hook
132. In facsimile technology, it is a number derived from the width-height ratio.
A. numerical aperture
B. scanning spot
C. index of cooperation
D. cut-off frequency
A. Recommended Jack
B. Released Jack
C. Registered Jack
D. Radio Jack
134. A cross-connect point used to distribute the larger feeder cable into smaller distribution
cables
A. SLIC
B. serving area interface
C. LATA
D. cross-connect cabinet
A. line turnaround
B. line conditioning
C. line sensing
D. line improvement
136. In telephony, functions that identify and connect subscribers to a suitable transmission path
A. transmission functions
B. signaling functions
C. switching functions
D. calling functions
137. The telephone switching plan that allows a certain degree of route selection when
establishing a phone call.
A. NPA
B. switching hierarchy
C. toll hierarchy
D. interoffice hierarchy
138. It provides access to the SS7 network access to databases used by switches inside and
outside of the network, and transfer of SS7 messages to other signaling points within the
network.
A. point codes
B. signaling points
C. service points
D. switching points
139. The connection between the subscriber and his own particular central office.
A. trunk
B. line
C. signaling
D. pulsing
140. It is a measure of how well we can distinguish closely spaced objects or identify small items
on a print.
A. resolution
B. legibility
C. contrast
D. hue
141. It is the exchange of signaling messages over local loops between stations and telephone
company switching machines
A. loop signaling
B. station signaling
C. interoffice signaling
D. pulse signaling
143. The talker hears a returned portion of the signal as an echo, what is the round-trip time of
delay for an echo to quite annoying?
A. 15 msec
B. 25 msec
C. 35 msec
D. 45 msec
144. When subscriber initiates a long distance calls, the local exchange connects the caller to the
toll office through a facility called ________.
A. 100 1000 uW
B. 10 100 uW
C. 10 1000 uW
D. 1000 10000 uW
A. 96 lpi
B. 150 lpi
C. 200 lpi
D. 400 lpi
A. FCC
B. DOD
C. CCITT
D. IEEE
148. Telephone set component placed directly across the tip and ring to alert the designation
party of an incoming call
A. transmitter
B. receiver
C. ringer
D. dialer
149. The reference frequency of a typical voice-band circuit is typically around _________.
A. 1500 Hz
B. 1300 Hz
C. 1700 Hz
D. 1800 Hz
150. The most versatile and popular crossbar switch was __________.
A. #4YB
B. 5#YB
C. #5XB
D. #5ZB
151. A telephone service that uses a common 800 area code regardless of the location of the
destination.
152. A device that combines the transmitter and the receiver to operate over the same wire pair.
A. balancing network
B. diaphragm
C. hybrid
D. relay
A. SSB
B. FSK
C. Vestigial sideband AM
D. PSK
154. A signal sent from the central office to a subscriber whenever there is an incoming call
A. busy signal
B. ringing signal
C. ringback signal
D. dial tone
155. It is defined as the optimum level of a test tone on a channel at some point in a
communications system.
156. A type of crosstalk which is caused by inadequate control of the frequency response of the
transmission system, poor filter design, or poor filter performance.
A. single-channel crosstalk
B. transmittance crosstalk
C. linear crosstalk
D. coupling crosstalk
157. Class of switching office that could provide service to geographical regions varying in size
from part of the state to all of several states, depending on population density.
A. sectional center
B. end office
C. regional center
D. toll center
158. By definition, speech power is equal to v.u. reading minus 1.4 dB plus log of N, where N is
159. The most commonly used light sensor in a modern fax machine is a
A. Phototube
B. Phototransistor
C. Liquid-crystal display
D. Charged coupled device
160. Systems that are simplex wireless communications systems designed to alert subscribers of
awaiting messages
A. paging
B. searching
C. texting
D. calling
A. crosstalk
B. interference
C. hits
D. jitter
162. Type of Class 4 toll center which provides human operators for both outward and inward
calling service.
A. Class 4P
B. Class 5
C. Class 4C
D. Class 1
164. Signals that provide the routing information, such as calling and called numbers.
A. routing
B. calling
C. controlling
D. addressing
166. 10 or more subscribers connected in a central office exchange using same local loop
A. wire tapping
B. party lines
C. eaves dropping lines
D. monitor lines
167. He designed and built the first transmitter and receiver for a telephone set.
168. If a switching machine is set to accept pulses at a rate of 10 pulses per second with a 60%
break, find the make interval of the switch.
A. 60 ms
B. 100 ms
C. 40 ms
D. 25 ms
169. How many point-to-point links are required to connect 50 telephones together?
A. 2255
B. 1225
C. 2250
D. 1552
A. Connecticut
B. Boston
C. Pennsylvania
D. Washington
A. 120
B. 25
C. 400
D. 195
A. 400 Hz
B. 100 Hz
C. 300 Hz
D. 500 Hz
A. 450 Hz
B. 500 Hz
C. 150 Hz
D. 250 Hz
176. The following frequencies are developed using 1.8 kHz used for scanner in facsimile,
except:
A. 300 Hz
B. 100 Hz
C. 450 Hz
D. 60 Hz
A. transmitter
B. receiver
C. mixer
D. oscillator
180. In fax, the following are scanner signals where the switcher switch in except:
A. 300 Hz
B. phasing signal
C. 90 Hz
D. map signals
A. AM
B. FM
C. PM
D. SSB
183. The helix wire forms one end of the circuit of facsimile; what forms the other?
A. insulated wire
B. drum
C. blade
D. transmit circuit
184. What emf is required across the circuit in facsimile to form a dark spot?
A. 40 V
B. 60 V
C. 25 V
D. 70 V
185. In a facsimile recorder what is used to make 1,500-Hz ac stronger than 2300 Hz?
187. If the tuning meter reads full scale, what would this indicate in facsimile?
A. 1300 signal
B. 2400 signal
C. 1400 signal
D. 1500 signal
188. If the tuning meter reads midscale, what would this indicate in facsimile?
A. average
B. mistuned
C. peak
D. minimum
189. If the tuning meter reads low-scale, what would this indicate in facsimile?
A. 1500 signal
B. 1700 signal
C. 2300 signal
D. 2400 signal
A. wears faster
B. wears slower
C. wears average speed
D. never wears
191. What should bring the left margin of the map to the left side of the paper in the recorder of
facsimile?
A. map signals
B. phasing signals
C. automatic switch
D. 90 Hz
FIBER OPTICS
Electronics Systems and Technologies
By
Melvin C. Arceo
ENCODED BY:
RIVERA, Billy Joe S.
1. A device that was constructed from mirrors and selenium detectors that transmitted sound
waves over a beam of light.
A. lightphone
B. photophone
C. cameraphone
D. walletphone
A. 3 repeaters
B. 8 repeaters
C. 11 repeaters
D. 20 repeaters
4. They were granted patents for scanning and transmitting television images through uncoated
fiber cables.
5. The product of the bit rate and distance of a fiber-optic system is 2 Gbits-km/s. What is the
maximum rate at 5 km?
A. 100 Mbits/s
B. 200 Mbits/s
C. 400 Mbits/s
D. 1000 Gbits/s
A. 20 MHz
B. 1 MHz
C. 100 MHz
D. 40 GHz
7. They experimented with light transmission cables through bundle of fibers and lead to the
development of flexible fiberscope.
A. forward bias
B. reverse bias
C. neither forward nor reverse bias
D. either forward or reverse bias
A. Kapany
B. Kao
C. Bockham
D. Keck
10. They wrote a paper describing how it was possible to use stimulated emission for amplifying
light waves (laser) as well as microwaves (maser).
A. Theodore Maiman
B. KC Kao and GA Bockham
C. Charles Townes and Arthur Schawlow
D. Kapron, Keck and Maurer
A. Charles Townes
B. GA Bockham
C. Theodore Maiman
D. ACS Van Heel
13. They proposed a new communication medium using cladded fiber cables.
16. The band of light frequencies that are too high to be seen by the human eye.
A. Ultraviolet
B. Visible light
C. Infrared
D. Yellow
A. PIN photodiode
B. Photovoltaic diode
C. Photodiode
D. Avalanche photodiode
A. 360 nm to 440 nm
B. 670 nm to 10^3 nm
C. 110 nm to 240 nm
D. 770 nm to 10^6 nm
A. Infrared
B. Visible light
C. Ultraviolet
D. Cosmic ray
A. pure
B. white
C. coherent
D. monochromatic
A. PIN photodiode
B. Photovoltaic diode
C. Photodiode
D. Avalanche photodiode
23. Range of wavelength of visible light
A. 670 nm to 10^3 nm
B. 440 nm to 540 nm
C. 110 nm to 240 nm
D. 390 nm to 770 nm
24. The band of light frequencies that are too low to be seen by the human eye
A. Infrared
B. X-rays
C. Visible
D. Ultraviolet
25. Which of the following terms best describes the reason that light is refracted at different
angles?
A. 670 nm to 10^3 nm
B. 440 nm to 540 nm
C. 110 nm to 240 nm
D. 10 nm to 390 nm
A. pure
B. intense
C. coherent
D. monochromatic
28. The coating in a fiber helps protect fiber from moisture, which reduces the possibility of the
occurrence of a detrimental phenomenon called
A. static fatigue
B. mechanical fatigue
C. stress fatigue
D. coating fatigue
30. The ratio of the speed of light in air to the speed of light in another substance is called
A. speed factor
B. index of reflection
C. index of refraction
D. speed gain
31. The three essential types of fiber commonly used today except:
32. What phenomenon will result if the glass fiber is exposed to long periods of high humidity?
A. stress fatigue
B. core corrosion
C. stress corrosion
D. cladding corrosion
33. The law that states When visible light of high frequency electromagnetic radiation
illuminates a metallic surface, electrons are emitted is known as ____________.
A. forward bias
B. reverse bias
C. neither forward nor reverse bias
D. either forward or reverse bias
A. normal state
B. above-ground state
C. excited state
D. spontaneous state
36. The process of decaying from one energy level to another energy level is called __________.
A. Spontaneous emission
B. Excited emission
C. Absorption
D. Any of these
37. The process of moving from one energy level to another is called ____________.
A. Spontaneous emission
B. Excited emission
C. Absorption
D. Spontaneous decay
38. Most fiber optic light sources emit light in which spectrum?
A. visible
B. infrared
C. ultraviolet
D. X-ray
39. A packet of energy which is equal to the difference between the two energy levels.
A. Photons
B. Electronvolt
C. Quantum
D. Quanta
40. It is the science of measuring only light waves that are visible to the human eye.
A. Radiometry
B. Photometry
C. Ophthalmology
D. Optometry
43. Which light emitter is preferred for high-speed data in a fiber-optic system?
A. incandescent
B. LED
C. neon
D. laser
44. Light intensity is generally described in terms of __________ and measured in _________.
45. In radiometric terms, it measures the rate at which electromagnetic waves transfer light
energy
A. Optical radiation
B. Optical impedance
C. Optical illusion
D. Optical power
46. It is described as the flow of light energy past a given point in a specified time
A. Optical radiation
B. Optical impedance
C. Optical illusion
D. Optical power
47. The term single mode and multimode are best described as
A. Radiant emission
B. Radiant power
C. Radiant flux
D. Radiant optics
49. In refraction that occurs in air/glass interfaces, among the visible light, which is bent the
most?
A. red
B. violet
C. yellow
D. green
50. Fiber-optic cables with attenuation of 1.8, 3.4, 5.9 and 18 dB are linked together. The total
loss is
A. 7.5 dB
B. 19.8 dB
C. 29.1 dB
D. 650 dB
51. In refraction that occurs in air/glass interfaces, among the visible light, which is the bent the
least?
A. violet
B. blue
C. red
D. orange
52. Ratio of the velocity of propagation of a light ray in free space to the velocity of propagation
of a light ray in free space in a given material.
A. refractive index
B. standing wave ratio
C. velocity factor
D. propagation velocity
53. It is the angle at which the propagating ray strikes the interface with respect to the normal.
A. refracted angle
B. incident angle
C. reflected angle
D. critical angle
54. It is the angle formed between the propagating ray and the normal after the ray has entered
the second medium.
A. angle of incidence
B. angle of reflection
C. propagation angle
D. angle of refraction
55. Between silicon and gallium arsenide, which has the greatest index of refraction?
A. Gallium arsenide
B. Neither of silicon nor gallium arsenide
C. Silicon
D. They are equal
56. A fiber-optic cable has a loss of 15dB/km. The attenuation in a cable 1000 ft long is
A. 4.57 dB
B. 9.3 dB
C. 24 dB
D. 49.2 dB
57. Medium 1 is a glass (n1=1.5) and medium 2 is an ethyl alcohol (n2=1.36). For an angle of
incidence of 30 degrees, determine the angle of refraction.
A. 44.5 degrees
B. 14.56 degrees
C. 33.47 degrees
D. 75 degrees
58. The minimum angle of incidence at which the light ray may strike the interface of two media
and result in an angle of refraction of 90 degrees or greater.
A. optimum angle
B. angle of refraction
C. refracted angle
D. critical angle
60. The maximum angle in which external light rays may strike the air/glass interface and still
propagate down the fiber.
A. acceptance angle
B. numerical aperture
C. index profile
D. refractive index
63. Only one path for light rays to take down the fiber
A. Multimode
B. Step-index
C. Single mode
D. Graded index
64. More than one path for light rays to take down the fiber
A. Multimode
B. Step-index
C. Single mode
D. Graded index
67. How many modes possible with a multimode step-index with a core diameter of 50 um, a
core refractive index of 1.6, a cladding refractive index of 1.584, and a wavelength of 1300 nm.
A. 456
B. 213
C. 145
D. 372
68. It is a graphical representation of the magnitude of the refractive index across the fiber.
A. mode
B. index profile
C. numerical aperture
D. refractive index
69. A type of index profile of an optical fiber that has a central core and outside cladding with a
uniform refractive index
A. multimode
B. graded index
C. step-index
D. single mode
70. A type of index of an optical fiber that has no cladding and whose central core has a non-
uniform refractive index.
A. graded index
B. multimode
C. single mode
D. step-index
71. Results in reduction in the power of light wave as it travels down the cable.
A. power loss
B. absorption loss
C. resistive loss
D. heat loss
A. reflection
B. absorption
C. scattering
D. dispersion
73. It is analogous to power dissipation to copper cables, impurities in the fiber absorb the light
and covert it to heat.
A. power loss
B. absorption loss
C. resistive loss
D. heat loss
74. It is caused by valence electrons in the silica material from which the fiber are manufactured.
75. It is a result of photons of light that are absorbed by the atoms of the glass core molecule.
A. single-mode step-index
B. multimode step-index
C. single-mode graded-index
D. multimode graded-index
78. For a single mode optical cable with 0.25dB/km loss, determine the optical power 100km
from a 0.1-mW light source.
A. -45 dBm
B. -15 dBm
C. -35 dBm
D. -25dBm
79. Light rays that are emitted simultaneously from an LED and propagated down an optical
fiber do not arrive at the far end of the fiber at the same time results to
A. intramodal dispersion
B. pulse length dispersion
C. modal dispersion
D. wavelength dispersion
80. Chromatic dispersion can be eliminated by __________.
81. Type of bend that occurs as a result of differences in thermal contraction rates between the
core and the cladding material.
A. Macrobending
B. Microbending
C. Quad bending
D. Constant-radius bending
82. These bends are caused by excessive pressure and tension and generally occur while fiber are
bent during handling or installation.
A. microbending
B. macrobending
C. constant-radius bending
D. kinks
A. 1.5 dB
B. 0.1 dB
C. 0.5 dB
D. 0.001 dB
84. It is caused by the difference in the propagation time of light rays that take different paths
down the fiber.
A. modal dispersion
B. microbending
C. Rayleigh scattering
D. chromatic dispersion
87. For a 300-m optical fiber cable with a bandwidth distance product of 600 MHz-km,
determine the bandwidth.
A. 5 GHz
B. 1 GHz
C. 2 GHz
D. 3 GHz
88. For an optical fiber 10 km long with a pulse spreading constant of 5 ns/km, determine the
maximum digital transmission rates using Return to Zero (RZ) and Nonreturn to Zero (NRZ).
A. 20 to 40 nm
B. 30 to 50 nm
C. 10 to 30 nm
D. 40 to 60 nm
A. 0.1 nm to 1 nm
B. 2 nm to 5 nm
C. 1 nm to 3 nm
D. 3 nm to 4 nm
91. When connector losses, splice losses and coupler losses are added, what is the limiting
factor?
A. source power
B. fiber attenuation
C. connector and splice loss
D. detector sensitivity
92. A pn-junction diode emits light by spontaneous emission
A. LED
B. APD
C. PIN
D. Zener diode
93. Which type of fiber optic cable is best for very high speed data?
A. single-mode step-index
B. multimode step-index
C. single-mode graded-index
D. multimode graded-index
A. Efficiency
B. Responsivity
C. Dark current
D. Spectral response
95. The leakage current that flows through a photodiode with no light input
A. dark voltage
B. dark impedance
C. dark power
D. dark current
96. The time it takes a light induced carrier travel across the depletion region of the
semiconductor.
A. dispersion
B. response time
C. irradiance
D. transit time
97. The range of wavelength values that a given photodiode will respond.
A. spectral response
B. permeance
C. dark current
D. reluctance
A. the time required for the signal to go from 10 to 90 percent of maximum amplitude
B. the ratio of the diode output current to the input optical power
C. the ratio of the input power to output power
D. the ratio of output current to input current
99. The minimum optical power a light detector can receive and still produce a usable electrical
output signal.
A. light responsivity
B. light sensitivity
C. light collectivity
D. illumination
100. Type of lasers that uses a mixture of helium and neon enclosed in glass tube.
A. gas lasers
B. solid lasers
C. semiconductor lasers
D. liquid lasers
101. Type of lasers that use organic dyes enclosed in glass tube for an active medium.
A. liquid lasers
B. plasma lasers
C. neon lasers
D. ruby lasers
A. 0.7 micrometer
B. 1.3 micrometer
C. 1.5 micrometer
D. 1.8 micrometer
103. Type of lasers that use solid, cylindrical crystals such as ruby
A. solid lasers
B. ILD
C. gas lasers
D. liquid lasers
104. Type of lasers that are made from semiconductor ph-junctions commonly called ILDs
A. semiconductor lasers
B. liquid lasers
C. plasma lasers
D. gas lasers
105. Which of the following is not a common application of fiber-optic cable?
A. computer networks
B. long-distance telephone system
C. closed-circuit TV
D. consumer TV
106. Total internal reflection takes place if the light ray strikes the interface at an angle with what
relationship to the critical angle?
A. less than
B. greater than
C. equal to
D. zero
A. 1:10
B. 10:1
C. 20:1
D. 1:20
A. single-mode step-index
B. multimode graded-index
C. single-mode graded-index
D. multimode step-index
A. 1 km
B. 2 km
C. 95 ft
D. 500 ft
113. The upper pulse rate and information-carrying capacity of a cable is limited by
A. pulse shortening
B. attenuation
C. light leakage
D. modal dispersion
A. air
B. glass
C. diamond
D. quartz
115. The core of fiber-optic cable is surrounded by
116. The speed of light in plastic compared to the speed of light in air is
A. less
B. more
C. the same
D. zero
119. The main benefit of light wave communications over microwaves or any other
communications media are
A. lower cost
B. better security
C. wider bandwidth
D. freedom from interface
A. infrared
B. ultraviolet
C. visible color
D. x-rays
A. 0.8 to 1.6 um
B. 400 to 750 nm
C. 200 to 660 nm
D. 700 to 1200 nm
A. bending of light
B. reflection of light waves
C. distortion of light waves
D. diffusion of light waves
124. Which of the following cables will have the highest launch power capability?
A. 50/125/0.2
B. 85/125/0.275
C. 62.5/125/0.275
D. 100/140/0.3
A. single-mode step-index
B. multimode step-index
C. single-mode graded index
D. multimode graded index
127. It refers to the abrupt of change in refractive index from core to clad
A. step index
B. graded index
C. semi-graded index
D. half step index
AMPLITUDE
MODULATION
Electronics Systems and Technologies
By
Melvin C. Arceo
ENCODED BY:
SANTOLLO, Dan Alvin
1. The process of impressing a low frequency information signals onto a high-frequency carrier
signal is called _____.
a. demodulation
b. oscillation
c. modulation
d. amplification
2. A silicon varactor diode exhibits a capacitance of 200pF at zero bias. If it is in parallel with a
60-pF capacitor and a 200-uH inductor, calculate the range of resonant frequency as the diode
varies through a reverse bias of 3 to 15V.
a. 679kHz to 2.13MHz
b. 966kHz to 1.15MHz
c. 355kHz to 3.12MHz
a. demodulation
b. damping
c. amplification
d. oscillation
4. It is the process of changing the amplitude of a relative high frequency carrier signal in
proportion with the instantaneous value of the modulating signal.
a. frequency modulation
b. digital modulation
c. phase modulation
d. analog modulation
a. carrier
b. upper sideband
c. lower sideband
d. modulating signal
a. linear mixing
b. analog multiplexing
c. signal summation
d. multiplexing
a. sidebands
b. modulating signal
c. envelope
d. carrier signal
a. tuned circuit
b. transformer
c. capacitor
d. inductor
a. coefficient of modulation
b. any of these
c. depth of modulation
d. modulation index
10. When the modulation index in an AM wave is greater than one it will cause _______.
a. any of these
b. splatter
c. overmodulation
d. buck-shot
a. 1
b. 0
c. 100
d. infinity
12. When the amplitude of the information in an AM modulator is equal to zero, what is the
value of the modulation index?
a. 1
b. 0
c. 100
d. infinity
14. When the modulation index is equal to zero, the total transmitted power is equal to
________.
b. carrier
c. double sidebands
d. an AM wave
15. When the modulation takes place prior to the output element of the final stage of the
transmitter, prior to the collector of the output transistor in a transistorized transmitter, this is
called ______.
a. high-level modulation
b. low-level modulation
c. zero-modulation
d. constant modulation
16. A circuit that monitors the received signal level and sends a signal back to the RF and IF
amplifiers to adjust their gain automatically.
17. When the modulation takes place in the final element of the final stage where the carrier
signal is at its maximum amplitude, it is called _____.
a. constant modulation
b. zero-modulation
c. low-level modulation
d. high-level modulation
18. If a superheterodyne receiver is tuned to a desired signal at 1000kHz and its conversion
(local) oscillator is operating at 1300kHz, what would be the frequency of an incoming signal
that would possibly cause image reception?
a. 1600 kHz
b. 2300 kHz
c. 1250 kHz
d. 3420 kHz
19. When modulation requires a much higher amplitude modulating signal to achieve a
reasonable percent modulation, this is called
a. high-level modulation
b. low-level modulation
c. zero-modulation
d. constant modulation
20. Amplitude modulators that vary the carrier amplitude with the modulating signal by passing
it through an attenuator work on principle of
a. rectification
b. resonance
c. variable resistance
d. absorption
21. A circuit which function is to raise the amplitude of the source signal to a usable level while
producing minimum nonlinear distortion adding as little thermal noise as possible.
a. power amplifier
b. non-linear amplifier
c. buffer amplifier
d. preamplifier
22. A circuit that has a low-gain, high-input impedance linear amplifier which is used to isolate
the oscillator from the high-power amplifiers.
a. power amplifier
b. bandpass filter
c. signal driver
d. buffer amplifier
23. With high-level transmitters, which of the following is not a primary function of the
modulator circuit?
d. it serves as a mixer
24. It is a form of amplitude distortion introduced when positive and negative alternations in the
AM modulated signal are not equal.
a. phase shift
b. carrier shift
c. amplitude variations
d. frequency shift
25. A carrier is simultaneously modulated by two sine waves with modulation indices of 0.3 and
0.4, the total modulation index
a. is 1
c. is 0.5
d. is 0.7
26. The component used to produce AM AT very high frequencies is a
a. varactor
b. thermistor
c. cavity resonator
d. PIN diode
a. carrier shift
b. amplitude variations
c. frequency shift
d. phase shift
a. carrier shift
b. amplitude variations
c. frequency shift
d. phase shift
29. It is a form of amplitude modulation where signals from two separate information sources
modulate the same carrier frequency at the same time without interfering with each other.
a. QPSK
b. QUAM
c. PSK
d. FSK
30. A receiver has a dynamic range of 81 dB. It has 0.55nW sensitivity. Determine the maximum
allowable input signal.
a. 59 mW
b. 69 mW
c. 79 mW
d. 88 mW
31. The information sources modulate the same carrier after it has been separated into two carrier
signals are at 90 degrees out of phase with each other.
a. QPSK
b. QUAM
c. PSK
d. FSK
32. Demodulating quadrature AM signal requires a carrier recovery circuit to reproduce the
original carrier frequency and phase and two balanced modulators to actually demodulate the
signals. This is called ________.
a. asynchronous detection
b. quadrature demodulation
c. synchronous detection
d. quadrature detection
34. Amplitude modulation generated at a very low voltage or power amplitude is known as
a. high-level modulation
b. low-level modulation
c. collector modulation
d. minimum modulation
35. It is the first stage of the receiver and is therefore often called the receiver front end.
a. mixer
b. RF section
c. local oscillator
d. IF stage
b. tuned modulator
c. class B RF amplifier
37. The section of the receiver than down-converts the received RF frequencies to intermediate
frequencies.
a. RF section
b. local oscillator
c. power amplifier
d. mixer
38. The circuit that demodulates the AM wave and converts it to the original information signal.
a. power amplifier
b. local oscillator
c. detector
d. IF section
39. A collector modulator has a supply voltage of 48V. The peak-to-peak amplitude of the
modulating signal for 100 percent modulation is
a. 24V
b. 48V
c. 96V
d. 120V
41. The noise reduction ratio achieved by reducing the bandwidth is called
a. dynamic range
b. noise figure
c. bandwidth efficiency
d. bandwidth improvement
42. It is the minimum RF signal level that can be detected at the input to the receiver and still
produce a usable demodulated information signal.
a. selectivity
b. sensitivity
c. Q-factor
d. bandwidth
a. m = 0
b. m = 1
c. m < 1
d. m > 1
46. It is defined as the difference in decibels between the minimum input level necessary to
discern the signal and the input level that will overdrive the receiver and produce distortion.
a. dynamic range
b. noise figure
c. bandwidth efficiency
d. bandwidth improvement
47. It is the input power range over which the receiver is useful.
a. dynamic range
b. noise figure
c. bandwidth efficiency
d. bandwidth improvement
48. It is defined as the output power when the RF amplifier response is 1-dB less than the ideal
linear gain response.
49. It is the measure of the ability of a communications system to produce, at the output of the
receiver, an exact replica of the original source information.
a. sensitivity
b. threshold
c. selectivity
d. fidelity
50. A SSB signal generated around a 200-kHz carrier. Before filtering, the upper and lower
sidebands are separated by 200 Hz. Calculate the filter Q required to obtain 40-dB suppression.
a. 1500
b. 1900
c. 2500
d. 2000
a. overmodulation
b. buffering
c. filtering
d. clipping
52. It is the total phase shift encountered by a signal and can generally be tolerated as long as all
frequencies undergo the same amount of phase delay.
53. ________ occurs when different frequencies undergo different phase shifts and may have a
detrimental effect on the complex waveform.
b. carrier only
c. one sideband
d. both sidebands
55. The circuit that recovers the original modulating information from an AM signal is known as
a
a. modulator
b. demodulator
c. mixer
d. crystal set
a. frequency distortion
b. digital distortion
c. phase distortion
d. amplitude distortion
b. demodulator
d. multiplexer
a. harmonic distortion
b. amplitude distortion
c. frequency distortion
d. phase distortion
a. amplitude distortion
b. phase distortion
c. harmonic distortion
d. frequency distortion
a. diode mixer
b. balanced modulator
c. envelope detector
d. crystal filter
b. phase distortion
a. time domain
b. frequency spectrum
c. amplitude modulation
d. frequency domain
63. It is a parameter associated with frequencies that fall within the passband of the filter.
a. coupling loss
b. diffusion loss
c. insertion loss
d. filter loss
64. A circuit that generates the upper and lower sidebands but no carrier is called
a. amplitude modulator
b. diode detector
c. class C amplifier
d. balanced modulator
a. HF point-to-point communications
b. monaural broadcasting
c. TV broadcasting
d. stereo broadcasting
66. It is generally defined as the ratio of the power transferred to a load with a filter in the circuit
to the power transferred to a load without a filter.
a. distortion loss
b. insertion loss
c. filter loss
d. harmonic loss
67. The modulation index of an AM wave is changed from 0 to 1. The transmitted power is
a. unchanged
b. halved
c. doubled
d. increased by 50 percent
68. The inputs to a balanced modulator are 1MHz and a carrier of 1.5 MHz. The outputs are
69. It is an indication of the reduction the signal-to-noise ration as a signal propagates through
the receiver.
a. noise figure
c. noise factor
d. signal-to-noise ratio
70. Types of receivers where the frequencies generated in the receiver and used for demodulation
are synchronized to oscillator frequencies generated in the transmitter.
a. coherent
b. asynchronous
c. non-coherent
d. none of these
71. Types of receiver where either no frequencies are generated in the receiver of the frequencies
used for demodulation are completely independent form the transmitter's carrier frequency.
a. synchronous
b. coherent
c. asynchronous
d. any of these
c. lattice modulator
a. frequency detection
b. noise detection
c. phase detection
d. envelope detection
a. TRF
b. transistorized
c. superhet
d. Armstrong
75. Which of the following is not true about the disadvantages of tuned radio frequency receiver?
a. their bandwidth is inconsistent and varies with center frequency when tuned over a
wide range of input frequencies
b. it is unstable due to the large number of RF amplifiers all tuned to the same center
frequency
c. their gains are not uniform over a very wide frequency range
b. switches
c. rectifiers
d. variable capacitors
77. It means to mix two frequencies together in a non-linear device or to translate on frequency
to another using non-linear mixing.
a. oscillation
b. heterodyne
c. modulation
d. amplification
78. An AM transmitter antenna current is measured with no modulation and found to be 2.6
amperes. With modulation, the current rises to 2.9 amperes. The percentage modulation is
a. 35%
b. 70%
c. 42%
d. 89%
79. Its primary purpose is to provide enough initial bandlimiting to prevent a specific unwanted
radio frequency from entering the receiver.
a. detector
b. predetector
c. preselector
d. mixer
80. It function is to reduce the noise bandwidth of the receiver and provides initial step
toward reducing the overall receiver bandwidth to the minimum bandwidth required to pass the
information signals.
a. preselector
b. detector
c. mixer
d. predetector
a. AM
b. FM
c. SSB
d. DSB
82. What is the first active device encountered by the received signal in the receiver?
a. mixer
b. RF amplifier
c. local oscillator
d. detector
a. bandpass filters
b. IF strip
c. IF filter
d. intermediate filters
a. audio detector
b. power detector
c. first detector
d. amplitude limiter
85. A carrier of 880kHz is modulated by a 3.5 kHz sine wave. The LSB and USB are,
respectively
a. LC networks
b. mechanical resonators
c. crystals
87. Its purpose of the detector section is to convert the IF signals back to the original source
information.
a. mixer
b. audio amplifier
c. converter
d. detector
88. It means that the two adjustments are mechanically tied together so that a single adjustment
will change the center frequency of the preselector, at the same time, change the oscillator
frequency.
a. high-side injecting
b. low-side injecting
c. gang tuning
a. linear devices
b. harmonic devices
c. class C amplifiers
d. nonlinear devices
90. When the local oscillator is tuned above the radio frequency, it is called
b. low-side injection
c. gang tuning
d. high-side injection
c. none of these
92. It is the ability of the local oscillator in a receiver to oscillate either above or below the
selected radio frequency carrier by an amount equal to the intermediate frequency throughout the
entire radio frequency brand.
a. tracking
b. mixing
c. heterodyning
d. tuning
93. The difference between the actual local oscillator frequency and the desired frequency is
called ________.
a. mixing error
b. gang error
c. tracking error
d. quantizing error
95. a crystal lattice filter has a crystal frequencies pf 27.5 and 27.502MHz. The bandwidth is
approximately
a. 2kHz
b. 3kHz
c. 27.501MHz
d. 55.502MHz
96. ___________ is any frequency other than selected radio frequency carrier that, if allowed to
enter a receiver and mix it with local oscillator, will produce a cross-product frequency that is
equal to the intermediate frequency
a. image frequency
b. intermediate frequency
c. aliasing frequency
d. ghost
97. It is a equivalent to a second radio frequency that will produce an IF that will interfere with
the IF from the desired radio frequency.
a. aliasing frequency
b. image frequency
c. interference
d. intermediate frequency
98. An SSB generator has a sideband filter centered at 3.0MHz. The modulating signal is 3kHz.
To produce both upper and lower sidebands, the following carrier frequencies must be produced:
b. noise figure
c. numerical aperture
d. signal-to-noise ratio
100. _________ occurs when a receiver picks up the same station at two nearby points on the
receiver tuning dial.
a. spurious pointing
b. under coupling
c. double spotting
d. optimal coupling
101. In the phasing method of SSB generation, one sideband is cancelled due out to
a. phase shift
b. sharp selectivity
c. carrier suppression
d. phase inversion
a. optimal coupling
b. double spotting
c. spurious pointing
d. under coupling
103. It is a high-gain, low noise, tuned amplifier that, when used is the first active encountered
by the receiver signal.
a. mixer
b. local oscillator
c. RF amplifier
d. detector
104. It is a high performance microwave receiver at the input stage. In the RF section of optimize
their noise figure.
a. high-power amplifier
c. buffer amplifier
d. local oscillator
a. transponder
b. product detector
c. converter
d. modulator
106. Which of the following is not the other name of a balanced modulator?
a. balanced mixer
b. product detector
c. product modulator
d. none of these
107. ________ amplifiers are relatively high gain tuned amplifiers that are very similar to RF
amplifiers, except that it operates over a relatively narrow, fixed frequency band.
a. IF amplifiers
b. low-noise amplifiers
c. buffer amplifiers
d. high-power amplifier
108. Type of tuned circuit where both the primary and secondary sides of the transformer are
tuned tank circuits
c. single-tuned circuit
d. LC tuned circuit
a. summer
b. multiplier
c. filter
d. mixer
a. class A
b. class B
c. class AB
d. class C
111. Its purpose is to down-convert the incoming radio frequencies to intermediated frequencies.
a. local oscillator
b. RF amplifier
c. detector
d. mixer
112. It is a non-linear amplifier similar to modulator, except that the output is turned to different
between the RF and local oscillator frequencies.
a. RF amplifier
b. local oscillator
c. mixer
d. detector
b. AM
c. linear summing
d. filtering
a. resistive coupling
b. inductive coupling
c. capacitive coupling
d. direct coupling
115. When the modulation index of an AM wave doubled, the antenna current is also doubled.
The AM system being used is
116. The ability of a coil to induce a voltage within its own windings is called
a. mutual inductance
b. coefficient coupling
c. self- inductance
d. inductance
117. If the carrier of a 100 percent modulated AM wave is suppressed the precentage power
saving will be
a. 50
b. 150
c. 100
d. 66.66
118. The ability of one coil to induce a voltage in another coil is called _________.
a. coefficient coupling
b. mutual inductance
c. inductance
d. self-inductance
a. balanced modulator
b. FET
c. diode modulator
a. Q factor
b. coefficient coupling
c. self-inductance
d. coefficient of modulation
121. Type of coupling where the secondary voltage is relatively low and the bandwidth is narrow.
a. tight coupling
b. optimum coupling
c. loose coupling
d. critical coupling
a. carrier
b. modulating signal
c. sidebands
d. envelope
123. Typer of coupling which has high gain and a broad bandwidth
a. optimum coupling
b. tight coupling
c. double coupling
d. loose coupling
124. It is the point where the reflected resistance is equal to primary resistance and the Q of the
primary tank circuit is halved and the bandwidth doubled.
a. critical coupling
b. tight coupling
c. loose coupling
d. optimum coupling
a. phase-shift circuit
b. crystal filter
c. resonant circuit
d. transformer
126. It is caused by the reactive element of the reflected impedance being significant enough to
change the resonant frequency of the primary tuned circuit.
a. optimum coupling
b. critical coupling
c. double peaking
d. flux linkage
127. IF transformers come as specially designed tuned circuits in groundable metal packages
called _______.
a. IF cans
b. IF container
c. IF strip
d. IF tetrapack
a. first detector
b. third detector
c. second detector
d. fourth detector
a. first detector
b. third detector
c. second detector
d. fourth detector
130. The two inputs to a mixer are the signal to be translated and a signal from
a. modulator
b. filter
c. antenna
d. local oscillator
a. phase detector
b. peak detector
c. frequency detector
d. transistor detector
132. A type of detector that detects the shape of the input envelope
a. peak detector
b. phase detector
c. diode detector
d. shape detector
133. The ratio of the peak modulating signal voltage to the peak carrier voltage is referred to as
a. voltage ratio
b. decibels
c. modulation index
d. mix factor
134. A circuit that automatically increases the receiver gain for weak RF input levels and
automatically decreases the receiver gain when a strong RF signal is received.
a. simple AGC
b. forward AGC
c. delayed AGC
d. complex AGC
136. The value Vmax and Vmin as read from AM wave on an oscilloscope are 3.0 and 2.8. The
percentage of modulation is
a. 10 percent
b. 41.4 percent
c. 80.6 percent
d. 93.3 percent
d. no other modulation system can provide the necessary bandwidth for high fidelity
138. Type of AGC that prevents the AGC feedback voltage from reaching the RF or IF amplifiers
until the RF level exceeds a predetermined magnitude.
a. forward AGC
b. delayed AGC
c. complex AGC
d. simple AGC
139. A circuit with a purpose to quiet a receiver in the absence of a received signal.
c. squelch circuit
140. A section of a audio stage of a receiver that removes sporadic, high amplitude noise
transients of short duration, such as impulse noise.
a. squelch circuit
b. clampers
c. clippers
d. peak detector
141. A circuit that detects the occurrence of a high-amplitude, short duration noise spike then
mutes the receiver by shutting off a portion of the receiver of the duration of the pulse.
a. squelch circuit
b. limiter
c. clamper
d. blanking circuit
142. The opposite modulation is
a. reverse modulation
b. downward modulation
c. unmodulation
d. demodulation
143. For good imag-frequency rejection, what is the desired value of the intermediate frequency?
a. relatively low IF
b. very low IF
c. relatively high IF
d. very high IF
144. With high-gain selective amplifiers that are stable and easily neutralized. what is the desired
value of intermediate frequency?
a. low IF
b. medium IF
c. high IF
d. very high IF
145. It is defined as the ratio of the demodulated signal level at the output receiver to the RF
signal level at the input to the receiver.
b. figure of merit
146. It is the process of modifying the characteristic of one signal in accordance with some
characteristic of another signal.
a. multiplexing
b. mixing
c. modulation
d. summing
147. The imaginary line on the carrier waveform of the amplitude modulated signal is called
__________.
a. sidebands
b. envelope
c. spurious emission
d. information
148. Indicate the false statement regarding the advantages of the phase cancellation method of
obtaining SSB over the filter method is false:
149. Indicate which one of the following advantages of the phase cancellation method of
obtaining SSB over the filter method is false:
d. There are more balanced modulators, therefore the carrier is suppressed better
a. mechanical
b. RC
c. LC
d. low-pass
152.One of the following cannot be used to remove the unwanted sideband in SSB. This is the
a. filter system
b. phase-shift method
c. third method
d. balanced modulator
154. To provide two or more voice circuits with the same carrier, it is necessary to use
a. ISB
b. carrier reinsertion
d. Lincomplex
155. A type of AGC is similar to conventional AGC except that the receive signal is monitored
closer to the front end of the receiver and the correction voltage is fed forward to the IF
amplifiers
a. ISB
b. delayed AGC
c. complex AGC
d. simple AGC
156. Having an information signal change some characteristics of a carrier signal is called
a. multiplexing
b. modulation
c. duplexing
d. linear mixing
157. A circuit that compensates for minor variations in the received RF signal level
159. A modulator circuit performs what mathematical operation on its two inputs?
a. addition
b. multiplication
c. division
d. square root
a. normal operation
b. carrier drops to 0
161. The outline of the peaks of a carrier has the shape of modulating signal and is called
_______.
a. trace
b. wave shape
c. envelope
d. carrier variation
162. Overmodulation occurs when
a. Vm > Vc
b. Vm < Vc
c. Vm = Vc
d. Vm = Vc = 0
a. spurious emission
b. harmonics
c. intermodulation products
d. sidebands
164. An AM signal has a carrier power of 5W, the percentage of modulation is 80 pecent. The
total power sideband is _________.
a. 0.8 W
b. 1.6 W
c. 2.5 W
d. 4.0 W
165. For 100 percent modulation, what percentage of power is in each sideband
a. 25 percent
b. 33.3 percent
c. 50 percent
` d. 100 percent
166. An AM transmitter has a percentage of modulation of 88, the carrier power is 440 W. The
power in one sideband is
a. 85 W
b. 110 W
c. 170 W
d. 610 W
a. SSB
b. vestigial sidebands
c. FM signal
d. DSB
168. It is a form of amplitude modulation in which the carrier is transmitted at full power, but
only one of the sidebands is transmitted.
a. SSBFC
b. SSBSC
c. SSBRC
d. ISB
169. With single-sideband full carrier, 100% modulation would mean a carrier power of how
many percent of the total transmitted power?
a. 80%
b. 20%
c. 50%
d. 40%
170. It is a form of amplitude modulation in which the carrier is suppressed and one of the
sidebands removed
a. SSBFC
b. ISB
c. vestigial sideband
d. SSBSC
171. It is a form of amplitude modulation in which one sideband is totally removed and the
carrier voltage is reduced to approximately 10% of its unmodulated amplitude
a. inderpendent sideband
b. SSBFC
c. SSBRC
d. SSBSC
a. vestigial sideband
b. DSBFC
c. independent sideband
d. SSBFC
173. It is a form of amplitude modulation in which the carrier and one complete sideband are
transmitted, but only part of the second sideband is transmitted.
a. independent sideband
b. vestigial sideband
c. DSBFC
d. SSBSC
174. It is the rms power developed at the crest of the modulation envelope of SSBSC.
a. carrier power
c. sideband power
a. power is conserved
c. bandwidth is conserved
d. tuning is easy
176.A circuit that produces a double sideband suppressed carrier signal is called ____________.
a. filter
b. mixer
c. demodulator
d. balanced modulator
d. any of these
178. A type of filter that receives electrical energy, converts it to mechanical vibrations and then
converts the vibrations back to electrical energy at its output.
a. crystal filter
b. mechanical filter
c. LC filter
d. SAW filter
179. A type of filter that uses acoustic energy rather than electromechanical energy to provide
excellent performance for precise bandpass filtering.
a. SAW filter
b. RC filter
c. mechanical filter
d. crystal filter
180. The difference between the IF and the BFO frequencies is called _________.
a. information signal
b. beat frequency
c. carrier signal
d. heterodyned signal
181. It is a circuit which is a narrowband PLL that tracks the pilot carrier in the composite
SSBRC receiver signal and uses the recovered carrier to regenerate coherent local oscillator
frequencies in the synthesizer.
b. mechanical filter
c. local oscillator
182. A system that provides narrowband voice communications for land mobile services with
nearly the quality achieved with FM systems and do it using less than one-third the bandwidth.
a. SSBSC
b. DSBFC
c. ACSSB
d. SSBAC
183. It is a process of combining transmissions from more than one source and transmitting them
over a common facility such as metallic or optical fiber cable or a radio-frequency channel.
a. buffering
b. modulation
c. multiplexing
d. demultiplexing
184. It is an analog method of combining two or more analog sources that originally occupied
the same frequency band in such a manner that the channels do not interfere with each other.
a. ATM
b. FDM
c. TDM
d. WDM
b. WDM
c. TDM
d. FDM
a. rms power
b. dc power
c. average power
b. tuned modulator
c. class B RF amplifier
188. Indicate in which one of the following only one sideband is transmitted:
a. H3E
b. A3E
c. B8E
d. C3F
189. One of the following cannot be used to remove the unwanted sideband in SSB. This is the
a. filter system
b. phase-shift method
c. third method
d. balanced modulator
191. To provide two or more voice circuits with the same carrier, it is necessary to use
a. ISB
b. carrier reinsertion
d. Lincomplex
a. upper
b. lower
c. neither
194. The output of an SSB transmitter with a 3.85 MHz carrier and a 1.5 kHz sine wave
modulating tone is
a. 192.2 W
b. 384.5 W
c. 769.2 W
d. 3077 W
a. average power
b. RMS power
197. An SSB transmitter has a PEP rating of 1 kilowatts. The average output power is in the
range of
a. 150 to 450 W
b. 100 to 300 W
c. 250 to 333 W
d. 3 to 4 kW
a. 100% modulation
b. 0% modulation
c. 50% modulation
d. overmodulated
199. What is the process in radio communication where the information or intelligent signal is at
lower frequency is put unto higher radio frequency for transmission to receiving station?
a. detection
b. mixing
c. modulation
d. demodulation
a. 1st IF signal
b. carrier signal
c. harmonics
d. 2nd IF signal
ANGLE MODULATION
Electronics Systems and Technologies
By
Melvin C. Arceo
ENCODED BY:
SANTOLLO, Dan Alvin
1. He developed the first successful FM radio system
a. B.E.Alpine
b. N.S. Kapany
c. E.H. Armstrong
2. Results whenever the phase angle of sinusoidal wave is varied with respect to time
a. angle modulation
b. digital modulation
c. amplitude modulation
d. pulse modulation
a. 60 kHz
b. 45 kHz
c. 30 kHz
d. 25 kHz
5. Varying the frequency of a constant -amplitude carrier directly proportional to the amplitude to
the modulating signal at a rate equal to the frequency of the modulating signal
a. amplitude modulation
b. angle modulation
c. phase modulation
d. frequency modulation
6. The amount of frequency deviation from the carrier center frequency in an FM transmitter is
proportional to what characteristic of the frequency signal?
a. amplitude
b. frequency
c. phase
d. shape
7. It is a modulation where the angle of a wave carrier is varied from its reference value
a. amplitude modulation
b. angle modulation
c. analog modulation
d. digital modulation
8. Both FM and PM are types of what kind of modulation?
a. amplitude
b. phase
c. angle
d. duty cycle
9. Varying the phase of a constant amplitude carrier displacement proportional to the amplitude
of the modulating signal at a rate equal to the frequency of the modulating signal.
a. amplitude modulation
b. angle modulation
c. phase modulation
d. frequency modulation
11. The relative angular displacement of the carrier phase in radians with respect to the reference
phase is called __________.
a. phase deviation
b. carrier deviation
c. frequency deviation
d. information deviation
12. If the amplitude of the modulating signal decreases, the carrier deviation
a. increases
b. decreases
c. remains constant
d. goes to zero
13. On an FM signal, maximum deviation occurs at what point on the modulating signal?
a. zero-crossing points
14. The amount of oscillator frequency increase and decrease around the carrier frequency is
called _________.
a. frequency deviation
b. phase shift
c. intelligence frequency
d. baseband
15. The relative displacement of the carrier frequency in hertz in respect to its unmodulated value
is called _____________.
a. frequency deviation
b. phase deviation
c. information deviation
d. carrier deviation
17. It is the instantaneous change in phase of the carrier at a given instant of time and indicates
how much phase of the carrier is changing with respect to its reference phase.
a. instantaneous frequency
b. instantaneous frequency deviation
c. instantaneous phase
18. Calculate the amount of frequency deviation caused by a limited noise spike that still cause
an undesired phase shift of 35 degrees when the input frequency is 5kHz.
a. 2.40kHz
b. 3.05kHz
c. 1.29kHz
d. 4.45kHz
a. intelligence frequency
b. frequency deviation
c. carrier frequency
d. broadband frequency
b. instantaneous phase
d. instantaneous frequency
21. In PM, a frequency shift occurs while what characteristic of the modulating signal is
changing?
a. shape
b. phase
c. frequency
d. amplitude
22. In FM, it is a device that in which amplitude variations are derived in response to frequency
or phase variations
a. detector
b. discriminator
c. demodulator
d. receiver
a. zero-crossing points
24. Since noise phase-modulates the FM wave, as the noise sideband frequency approaches the
carrier frequency, the noise amplitude
a. remains constant
b. is decreased
c. is increased
d. is equalized
25. It is the instantaneous change in frequency of the carrier and is defined as the first time
derivative of the phase deviation
a. instantaneous frequency
c. instantaneous phase
26. Since noise phase- modulates the FM wave, as the noise sideband frequency approaches the
carrier frequency, the noise amplitude
a. remains constant
b. is decreased
c. is increased
d. is equalized
27. It is the precise frequency of the carrier at a given instant of time is defined as the first time
derivative of the instantaneous phase.
a. instantaneous frequency
c. instantaneous phase
28. It is the output-versus-input transfer functions for modulators which give the relationship
between the output parameter changes in respect to specified changes in the input signal.
a. frequency deviation
b. deviation sensitivity
c. transconductance curve
d. phase deviation
29. When the modulating frequency is doubled, the modulation index is halved, and the
modulating voltage remains constant. The modulation system is
a. amplitude modulation
b. phase modulation
c. frequency modulation
31. To compensate for increases in carrier frequency deviation with an increase in modulating
signal frequency, what circuit is used between the modulating signal and phase modulator?
a. low-pass filter
b. high-pass filter
c. phase shifter
d. bandpass filter
32. Indicate which one of the following is not an advantage of PM over AM:
33. With phase modulation, the maximum frequency deviation occurs during what value of the
modulating signal?
b. rms value
d. zero crossings
34. With frequency modulation, maximum frequency deviation occurs _____ of the modulation
signal.
d. zero crossings
a. modulation index
b. frequency deviation
c. phase deviation
d. instantaneous phase
37. The FM produced by PM is called
a. FM
b. PM
c. indirect FM
d. indirect PM
39. If the amplitude of the modulating signal applied to a phase modulator is constant, the output
signal will be
a. zero
40. To prevent overloading of the last IF amplifier in the receiver, one should use the
a. squelch
b. variable sensitiivity
c. variable selectivity
d. double conversion
a. phase deviation
c. carrier swing
d. instantaneous frequency
42. A 100MHz carrier is deviated 50 kHz by 4kHz signal. The modulation index is
a. 5
b. 8
c. 12.5
d. 20
43. With angle modulation, it is defined as the ratio of the frequency deviation actually produced
to the maximum frequency deviation allowed by law stated in percent form.
a. modulation index
b. percent modulation
c. frequency deviation
d. phase deviation
44. In a broadcast FM system, the input S/N = 4. Calculate the worst case S/N at the output if the
receiver's internal noise effect is negligible.
a. 19.8:1
b. 21.6:1
c. 23:1
d. 15:1
45. It is a circuit in which the carrier is varied in such a way that its instantaneous phase is
proportional to the modulating signal.
a. frequency modulators
b. amplitude modulators
c. phase modulators
d. mixers
c. the output is twice that obtainable from the similar phase discriminator
d. the circuit is the same as in a discriminator, except that the diodes are reversed
a. 0.2
b. 5
c. 8
d. 40
a. unrest frequency
b. rest frequency
c. frequency-modulated frequency
d. carrier frequency
49. It is a circuit in which the carrier is varied in such a way that its instantaneous phase is
proportional to the integral of the modulating signal
a. phase modulator
b. phase deviator
c. amplitude deviator
d. frequency modulator
b. frequency deviators
c. phase modulators
d. amplitude deviators
52. A 70 kHz carrier has a frequency deviation of 4 kHz with a 1000Hz signal. What is the
bandwidth of the FM signal?
a. 4kHz
b. 7kHz
c. 10 kHz
d. 28 kHz
53. The controlled oscillator synthesizer is sometimes preferred to the direct one because
a. PM modulator
b. FM modulator
c. PM demodulator
d. FM demodulator
a. PM modulator
b. PM demodulator
c. FM modulator
d. FM demodulator
a. PM modulator
b. FM modulator
c. PM demodulator
d. FM demodulator
a. 24kHz
b. 33.6kHz
c. 38.8kHz
d. 48kHz
a. PM modulator
b. FM modulator
c. PM demodulator
d. FM demodulator
60. A receiver has poor IF selectivity. It will therefore also have poor
a. blocking
b. double-spotting
c. diversity reception
d. sensitivity
a. variable selectivity
c. double spotting
d. double conversion
62. He mathematically proved that for a given modulating signal frequency a frequency-
modulated wave cannot be accommodated in a narrower bandwidth than an amplitude modulated
wave.
a. R.C. Alpine
b. E.H. Armstrong
c. J.R. Carson
d. J.J. Thomson
63. The maximum allowed deviation of the FM sound signal in TV is 25 kHz. If the actual
deviation is 18kHz, the percent modulation is
a. 43 percent
b. 72 percent
c. 96 percent
d. 139 percent
64. The local oscillator of a broadcast receiver is tuned to a frequency higher than the incoming
frequency
a. greater efficiency
b. noise immunity
c. capture effect
a. wideband FM
b. narrowband FM
c. commercial FM
d. medium FM
67. For high-index signal, a method of determining the bandwidth is called ________ approach
a. quasi-stationary
b. quasi-movement
c. quasi-deviation
d. any of these
68. When a receiver has a good blocking performance, this means that
69. He established a general rule to estimate the bandwidth for all angle-modulated system
regardless of the modulation index.
a. R.C. Alpine
b. E.H. Armstrong
c. J.R. Carson
d. J.J. Thomson
70. An AM receiver uses a diode detector for demodulation. This enables it satisfactority to
receive
a. single-sideband, suppressed carrier
c. independent sideband
c. noise susceptibility
d. lower efficiency
72. A rule that approximates the bandwidth necessary to transmit an angle-modulated wave as
twice the sum of the peak frequency deviation and the highest modulating frequency.
a. Carson's rule
b. Shannon's rule
c. Hartley's law
d. Hartley-Shannon law
73. It is the worst case modulation index and is equal to the maximum peak frequency deviation
divided by the maximum modulating signal frequency
b. frequency deviation
c. deviation ratio
a. modulator
b. demodulator
c. limiter
d. low-pass filter
75. The phenomenon of a strong FM signal dominating a weaker signal on a common frequency
is referred to as the
a. capture effect
b. blot out
c. quieting factor
d. domination syndrome
76. The highest side frequencies form one channel are allowed to spill over into adjacent
channels producing an interference known as _________.
a. co-channel interference
c. splatter
d. overmodulation
a. high-pass filter
b. band-stop filter
c. low-pass filter
d. bandpass filter
78. Frequency modulation transmitters are more efficient because their power is increased by
what type of amplifier?
a. class A
b. class B
c. class C
a. sinusoidal
b. non-sinusoidal
c. low frequencies
d. high frequencies
b. band-stop filter
c. low-pass filter
d. bandpass filter
a. integrator
b. differentiator
a. integrator
b. differentiator
a. high frequencies
b. mid-range frequencies
c. low frequencies
c. crystal oscillators are inhrently stable and therefore more difficult for them to
achieve high phase deviations and modulation indices
d. carrier oscillator is isolated form the actual modulator circuit and therefore can be
stable source.
85. It is an angle modulation in which the frequency of the carrier is deviated by the modulating
signal
a. direct PM
b. PM
c. indirect FM
d. any of these
a. heterodyning
b. amplification
c. modulation
d. none of these
a. low-pass filter
b. high-pass filter
c. phase shifter
d. bandpass filter
a. phase inverter
b. bandpass filter
c. high-pass filter
d. low-pass filter
89. A circuit that compares the frequency of the noncrystal carrier oscillator to a crystal reference
oscillator and then produces a correction voltage proportional to the difference between the two
frequencies
a. AFC
b. squelch circuit
c. AGC
d. heterodyning circuit
90. A frequency selective device whose output voltage is proportional to the difference between
the input frequency and its resonant frequency
a. modulator
b. squelch circuit
c. frequency discriminator
d. FM transmitters
91. Allows FM receiver to differentiate between two signals received with the same frequency
but different amplitudes
a. flywheel effect
b. amplitude limiting
c. noise immunity
d. capture effect
92. If an FM transmitter employs one doubler, one tripler, and one quadrupler, what is the carrier
frequency swing when the oscillator frequency swing is 2kHz?
a. 24 kHz
b. 48 kHz
c. 14 kHz
d. 12 kHz
a. 1 kHz
b. 2.122 kHz
c. 5 kHz
d. 75 kHz
a. wide bandwidth
b. complex
c. high cost
d. less noise
a. preselector
b. detector
c. IF amplifier
d. mixer
96. In FM receivers, which of the following provides most gain and selectivity of the receiver?
a. detector
b. RF amplifier
c. local oscillator
d. IF amplifier
a. PIN diode
b. varactor diode
c. snap diode
98. The depletion region in a junction diode forms what part of a capacitor?
a. plates
b. leads
c. package
d. dielectric
99. Which of the following removes the information from the modulated wave in FM receivers?
a. amplifiers
b. mixer
c. speakers
d. discriminator
a. tuned amplifier
b. limiter
c. passband filter
d. any of these
101. _________ are frequency-dependent circuits designed to produce an output voltage that is
proportional to the instantaneous frequency at its output
a. PM receivers
b. PM demodulators
c. FM demodulators
d. FM receivers
102. Increasing the reverse bias on a varactor diode will it cause its capacitance to
a. decrease
b. increase
d. drop to zero
b. nF
c. uF
d. F
104. Which of the following is the simplest form of tuned-circuit frequency discriminator?
a. Foster-Seeley discriminator
b. Ratio detector
c. slope detector
d. PLL detector
105. It is simply two single-ended slope detectors connected in parallel and fed 180 degrees out
phase.
a. Foster-Seeley discriminator
b. quadrature detector
d. PLL detector
a. zero
b. small
c. medium
d. large
a. carrier
b. modulating signal
c. modulating voltage
d. sideband frequency
108. Which of the following tuned-circuit frequency discriminator is relatively immune to
amplitude variations in its input signal?
a. ratio detector
b. slope detector
d. quadrature detector
a. quadrature demodulator
b. PLL demodulator
c. Foster-Seely discriminator
d. ratio detector
a. RC low-pass filter
b. RC high-pass filter
c. LR low-pass filter
d. LC resonant circuit
111. An FM receiver provides 100dB of voltage gain prior to the limiter. Calculate the receiver's
sensitivity if the limiter's quieting for an FM receiver is 300mV?
a. 4.5 uV
b. 3.0 uV
c. 2.1 uV
d. 1.3 uV
112. The small frequency change produced by a phase modulator can be increased by using
___________.
a. amplifier
b. mixer
c. frequency multiplier
d. frequency divider
a. threshold voltage
b. capture level
c. quieting level
d. any of these
114. The inherent ability of FM to diminish the effects of interfering signals is called _______.
a. capture effect
b. noise suppression
115. A crystal oscillator whose frequency can be changed by an input voltage is called _______.
a. VCO
b. VXO
c. VFO
d. VHF
116. Which oscillators are preferred for carrier generators because of their good frequency
stability?
a. LC
b. RC
c. LR
d. crystal
a. Foster-Seely discriminator
b. Pulse-averaging discriminator
c. quadrature detector
d. PLL
118. Provides a slight automatic control over the local oscillator circuit and compensates for its
drift that would otherwise cause a station to become detuned.
a. AGC
b. AFC
c. VVC
d. VCO
119. ________ of an FM receiver is the maximum dB difference signal strength between two
received signals necessary for the capture effect to suppress the weaker signal.
a. capture effect
b. capture gain
c. capture ratio
d. capture loss
120. When two limiter stages are used, there is called ___________.
a. double limiting
b. two-time limiting
c. reserve limiting
d. ratio limiting
a. ratio detector
b. PLL
c. quadrature detector
d. pulse-averaging discriminator
a. ratio detector
b. PLL
c. quadrature
d. pulse-averaging discriminator
a. baffle
b. base
c. tweeter
d. woofer
125. Each speaker assembly at the receiver reproduces exactly the same information
a. monophonic
b. multiphonic
c. stereophonic
d. any of these
a. astable multivibrator
b. zero-crossing detector
c. one-shot
d. low-pass filter
127. A reactance modulator looks like a capacitance of 35pF in parallel with the oscillator-tuned
circuit whose inductance is 50 uH and capacitance is 40 pF. What is the center frequency of the
oscillator prior to FM?
a. 1.43 MHz
b. 2.6 MHz
c. 3.56 MHz
d. 3.8 MHz
a. 38 kHz
b. 15 kHz
c. 67 kHz
d. 53 kHz
a. 50 Hz to 15 kHz
b. 60 kHz to 74 kHz
c. 23 kHz to 53 kHz
d. 20 Hz to 20 kHz
130. An FM demodulator that uses a differential amplifier and tuned circuits to convert
frequency variations into voltage variations is the
a. quadrature detector
b. Foster-Seeley discriminator
d. phase-locked loop
131. The output amplitude of the phase detector in a quadrature detector is proportional to
a. pulse width
b. pulse frequency
c. input amplitude
d. the phase shift value at center
132. The output to a PLL is 2MHz. In order for the PLL to be locked. The VCO output must be
a. 0 MHz
b. 1 MHz
c. 2 MHz
d. 4 MHz
a. 75 kHz
b. 15 kHz
c. 25 kHz
d. 3 kHz
a. 50 Hz to 15 kHz
b. 60 kHz to 74 kHz
c. 23 kHz to 53 kHz
d. 20 Hz to 20 kHz
135. The band of frequencies over which a PLL will acquire or recognize an input signal is called
the
a. circuit bandwidth
b. capture range
c. band of acceptance
d. lock range
136. The three primary frequency bands are allocated by FCC for two-way FM radio
communications except:
a. 25 kHz
b. 5 kHz
c. 75 kHz
d. 3 kHz
138. Decreasing the input frequency to be locked PLL will cause the VCO output to
a. decrease
b. increase
c. remains constant
139. The range of frequencies over which a PLL will track input signal variations is known as the
a. circuit bandwidth
b. capture range
c. band of acceptance
d. lock range
140. The maximum modulating signal frequency for two-way transmitter is typically
a. 3 kHz
b. 5 kHz
c. 15 kHz
d. 75 kHz
a. low-pass filter
b. bandpass filter
c. tunable oscillator
d. frequency modulator
a. low-pass filter
b. VCO
c. phase detector
d. none of these
a. capture effect
b. noise immunity
d. FM is more efficient
144. The usual cutoff frequency of pre-emphasis and de-emphasis in broadcast FM?
a. 50 Hz
b. 75 Hz
c. 2122 Hz
d. 3183 Hz
a. 2500
b. 5
c. 1.67
d. 75
a. Foster-Seeley discriminator
b. ratio detector
c. slope detector
d. PLL
147. The range of frequencies over which the PLL will capture an input signal is known as
________.
a. lock range
b. capture range
c. bandwidth
d. sidebands
a. ratio detector
b. quadrature detector
c. PLL
d. pulse-averaging discriminator
a. ratio detector
b. PLL
c. quadrature detector
d. crosby modulator
150. The range of frequencies over which a PLL will track an input is called
a. lock range
b. capture range
c. track range
d. driving range
a. 25 kHz
b. 75 kHz
c. 50 kHz
d. 125 kHz
a. 25 kHz
b. 75 kHz
c. 50 kHz
d. 125 kHz
d. is not transmitted
a. a 19 kHz subcarrier
b. a 38 kHz subcarrier
c. a 67 kHz subcarrier
a. reactance modulator
b. balanced modulator
c. varactor diode modulation
d. armstrong system
157. In an FM system, if the modulation index is doubled by halving the modulating frequency,
what will be the effect on the maximum deviation?
b. doubles
c. decrease by 1/2
d. increase by 1/4
158. Determine from the following the common use of DSB in broadcast and
telecommunication.
a. satellite communications
b. FM/TV stereo
c. two-way communications
d. telephone systems
a. F3F
b. G3E
c. F3E
d. F3C
160. The range of frequencies over which a PLL will cause the input of the VCO signals to
remain synchronized is known as the _________ range.
a. capture
b. lock
c. acquisition
d. any of these
161. If the PLL input is zero, the VCO will operate at its ____________ frequency.
a. free-running
b. natural
c. operating
d. any of these
162. Since a PLL will only respond to signals over a narrow frequency range, it acts likes a
________.
a. low-pass filter
b. high-pass filter
c. bandpass filter
d. bandstop filter
163. In a PLL demodulating an FM signal, the VCO output is an exact reproduction of the
___________.
a. modulating signal
b. carrier signal
c. carrier amplitude
d. VCO output
164. In a PLL demodulating an FM signal, the VCO output is an exact reproduction of the
________.
a. FM input
b. VCO input
c. modulating signal
d. error signal
165. After the IF stages have been aligned, the next state to align in FM receiver is
a. local oscillator
b. limiter stage
c. RF amplifier
d. mixer stage
a. frequency-shift keying
b. two-tone modulation
c. purse-code modulation
d. single-tone modulation
a. Facsimile
b. RTTY
c. modulated CW
d. television
c. an FM generator
a. television video
d. television audio
a. to compete with AM
b. to overcome noise
c. to increase listeners
d. to supplement AM
a. amplitude
b. frequency
c. phase
d. phase shift
a. broadcast
b. TV video
c. mobile communications
d. amateur radio
173. Under what condition would a 1 kHz AF signal produce a single pair of FM sidebands?
a. wideband
b. broadcast FM
c. TV audio FM
d. narrowband FM
a. 75 kHz
b. 220 kHz
c. 270 kHz
a. 75 kHz
b. 50 kHz
c. 25 kHz
d. 15 kHz
a. 50 Hz
b. 30 Hz
c. 10 Hz
d. 5 Hz
b. less AF distortion
c. less AF out
d. no filtering of carrier
178. What is the unction of the dc that comes out of the dc amplifier in a PLL-type FM detector?
a. carrier signal
b. filter signal
c. error signal
d. phase signal
179. What is the function of the dc that comes out of the dc amplifier in a PLL-type FM
detector?
a. oscillators
b. AF signal
c. RF signal
d. carrier signal
a. less AF distortion
b. greater AF out
c. less RF out
d. less RF distortion
181. What band for high-Q coils be more desirable for stagger-tuned-type discriminator
transformer?
a. wide
b. intermediate
c. interfacing
d. narrow
a. varying DC
b. varying AC
c. steady DC
d. steady AC
183. In a stagger-tuned discriminator, the AF output voltage is _________.
a. varying DC
b. varying AC
c. steady DC
d. steady AC
a. steady AC
b. varying AC
c. steady DC
d. varying DC
a. steady DC
b. varying AC
c. varying DC
d. steady AC
186. Which of the following discriminator circuits require limiters ahead of them?
a. quadrature detector
b. foster-seeley discriminator
c. slope detector
d. stagger-tuned
187. Which of the following discriminator circuits provide an automatic gain control voltage?
a. ratio detector
c. quadrature detector
d. stagger-tuned detector
188. Which of the following discriminator circuits has its diodes in series?
a. ratio
b. quadrature detector
c. round-travis detector
d. slope detector
189. To what frequency must the gated-beam quadrature circuit be tuned in a TV receiver?
a. 10.7 MHz
b. 455 kHz
c. 70 MHz
d. 4.5 MHz
190. To what frequency must the gated-beam quadrature circuit be tuned in an FM broadcast
receiver?
a. 4.3 MHz
b. 10.7 MHz
c. 11 MHz
d. 4.8 MHz
a. foster-seeley detector
b. ratio detector
c. quadrature detector
d. phase-locked loop
a. increase amplitude
c. amplify RF signal
194. What are the two types of stages in an FM receiver that differ from those in an AM
receiver?
195. What special circuits are used in a squelch system that can follow changing noise levels?
a. noise amplifiers
b. rectifier
c. dc amplifier
d. any of these
c. reduce flutter
a. Crosby
b. Foster-Seeley
c. Round Travis
d. Messier
199. What effect would be produced if a small inductance were used in plasce of the 50 pF
capacitance in the reactance-tube modulator?
d. any of these
200. The following are significant circuits in the AFC system except:
a. crystal
b. mixer
c. IF
d. filter
201. Besides the reactance-tube modulator, what is another method of producing direct FM?
a. armstrong modulator
c. impeadance modulator
d. slug indicator
d. simplicity
a. Arc transmitter
b. MOPA
c. Armstrong
d. crystal
a. any of these
d. prevent overdeviation
d. any of these
206. What signals might feed into an FM broadcast station audio control console?
a. microphones
b. turntables
c. remote lines
d. any of these