Republic of the Philippines

Smart EDGE ECE REVIEW SPECIALIST

BOARD OF ELECTRONICS ENGINEERING
ELECTRONICS ENGINEER LICENSURE EXAMINATION

Intensive and Comprehensive Exam in Electronics 8

INSTRUCTION: Do not write anything on this questionnaire. Select the correct answer for each of the following questions. Mark only one answer for
each for each item by shading the box corresponding to the letter of your choice on the answer sheet provided.

1. One of the most common applications of a potentiometer is as an adjustable voltage divider, also known as
A. voltage control B. current control C. volume control D. divider control
2. In the given circuit, what type of failure will cause the voltage at point B to equal the
voltage at point C?
A. R1 shorts B. R2 shorts C. R3 shorts D. R2 opens
3. An 8-ohm resistor is in series with a lamp. The circuit current is 1 A. With 20 V applied, what voltage is
being allowed for the lamp?
A. 4 V B. 8 V C. 12 V D. 20 V
4. A string of resistors in a series circuit will:
A. divide the source voltage in proportion to their values
B. reduce the power to zero
C. cause the current to divide
D. increase the source voltage in proportion to the values
5. Given a series circuit containing resistors of different values, which statement is not true?
A. The current through each resistor is the same.
B. The sum of the voltage drops across each resistive element will be equal.
C. The total resistance is the sum of the value of the resistors.
D. The voltage drop across each resistor is the same.
6. If R2 opens in the given circuit at no. 2, what is the voltage at point B?
A. +19.2 V B. +8.8 V C. +28 V D. –19.2 V
7. When a battery is connected to a series circuit, it delivers current based only upon:
A. primary/secondary difference B. total resistance
C. the polarity connections D. average resistance
8. If two resistors have the same voltage drop in a series circuit, it means:
A. they are connected in parallel B. they are of unequal value
C. the voltage has doubled D. they are of equal value
9. The current flowing through an unloaded voltage divider is called the:
A. resistor current B. load current C. bleeder current D. voltage current
10. With 21 V applied, if R1 = 5 ohms, R2 = 35 ohms, and R3 = 14 ohms, what is the current of R2 if R1 is series
connected with parallel circuit R2 and R3?
A. 200 mA B. 800 mA C. 600 mA D. 400 mA
11. What is the total resistance?
A. 2.2 k B. 3.2 k C. 4.2 k D. 5.2 k
12. The first goal to accomplish in analyzing a complex series-parallel circuit is to
A. equate all parallel components B. equate all series components
C. solve for all the voltage drops D. solve for the total current and resistance
13. If R1 is in series with parallel connected to R2 and R3, what happens to total current if R2 opens?
A. increases B. decreases C. remains the same D. cannot tell
14. If R1 is in series with a parallel combination of R2, R3, and R4, when the resistance value of R2 increases,
the voltage across R3 will
A. increase B. decrease C. remain the same D. Cannot tell
15. What is the power dissipated by R1, R2, and R3?
A. P1 = 0.13 W, P2 = 0.26 W, P3 = 0.12 W B. P1 = 0.26 W, P2 = 0.52 W, P3 = 0.23 W
C. P1 = 0.52 W, P2 = 0.92 W, P3 = 0.46 W D. P1 = 1.04 W, P2 = 1.84 W, P3 = 0.92 W
16. As current travels within a conductor:
A. the magnetic field aids the current B. a magnetic field is developed around it
C. the wire tries to point north D. an electrostatic field opposes the current
17. A series RL filter circuit with an output across the inductor will result in what type of filtering?
A. passing of the higher frequencies B. passing of the lower frequencies
C. blocking of the higher frequencies D. blocking of a certain range of frequencies
18. On a schematic, dashed lines between two vertical coils usually mean the transformer has:
A. an air core B. an iron core C. a nonmetallic core D. a ferrite core
19. What is the number of turns required in the secondary winding for a transformer when 120 volts is applied to
a 2400-turn primary to produce 7.5 Vac at the secondary?
A. 75 turns B. 150 turns C. 900 turns D. 1920 turns
20. A magnetic circuit breaker will open to protect equipment only when:
A. voltage is exceeded B. an open is in the equipment
C. the equipment is operating properly D. current is exceeded
21. During a current change, the ability of a conductor to produce counter emf within itself is called:
A. back emf B. self-induction C. a henry D. impedance
22. What will happen when an inductor's magnetic field collapses?
A. Current will double. B. Voltage will be induced.
C. A new field will expand. D. Counter emf will be high.
23. When a magnet enters a coil and a voltage is induced, the process is known as:
A. an alternation B. self-inductance C. counter emf D. flux linkage
24. When current in an inductor starts to change, it cannot react instantly due to:
A. fixed coil resistance B. eddy current generation
C. applied emf of the circuit D. the counter emf of the coil
25. What is the inductive reactance?
A. 5.2 B. 7.5 C. 1.3 k D. 7.5 k

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26. Which coil would be used as a step-up transformer primary if coil number 1 has 100 more turns than coil
number 2?
A. The coil windings must be the same. B. coil 1 C. The coil ratio is too small. D. coil 2
27. A transformer is used:
A. to couple electric energy from one dc circuit to another
B. to couple electric energy from an ac circuit to a dc circuit
C. to couple electric energy from a dc circuit to an ac circuit
D. to couple electric energy from one ac circuit to another
28. Indication of transformer primary and secondary voltage relationships is accomplished by:
A. color-coded wires B. dot notation C. black, rather than gray, casings D. winding ratios
29. What is the name of the part inside a relay that is moved by the action of the electromagnet?
A. armature B. conductor C. contacts D. solenoid
30. Which transformer turns ratio is needed to match two 16-ohm parallel devices to an output of 22.2 ohms?
A. 1.38:1 B. 1.67:1 C. 0.72:1 D. 0.60:1
31. What happens when moving expanding lines of force encounter a conductor?
A. Current increases. B. Voltage is induced.
C. Resistance is reduced. D. Power is increased.
32. What is the maximum source current for a transformer rated at 10 kVA, 1000/500 60 Hz?
A. 2 A B. 5 A C. 10 A D. 20 A
33. What are the properties that determine the inductance of a coil?
A. Length of wire, number of turns, type of core material, length of core
B. Number of turns, type of wire, length of core, and cross-sectional area of core
C. Type of core material, number of turns, cross-sectional area of core, and length of core
D. Type of core material, type of wire, number of turns, and cross-sectional area of core
34. When a load is not connected to the secondary of a transformer:
A. primary current is zero
B. primary current is inversely proportional to primary impedance
C. secondary voltage is zero
D. secondary voltage is proportional to primary impedance
35. What circuit activity may shift a characteristic curve so that diode operating points are different?
A. higher power (heat) B. higher resistance C. lower voltage D. lower current
36. If a 169.7 V half-wave peak has an average voltage of 54 V, what is the average of two full-wave peaks?
A. 119.9 V B. 108.0 V C. 115.7 V D. 339.4 V
37. A filtered full-wave rectifier voltage has a smaller ripple than does a half-wave rectifier voltage for the
same load resistance and capacitor values because:
A. there is a shorter time between peaks B. there is a longer time between peaks
C. the larger the ripple, the better the filtering action D. none of the above
38. Shunting the ac component away from the load is the task of a:
A. transformer B. filter C. regulator D. rectifier
39. Why is heat produced in a diode?
A. due to current passing through the diode B. due to voltage across the diode
C. due to the power rating of the diode D. due to the PN junction of the diode
40. With full-wave rectification, current through the load resistor must be:
A. in opposite directions B. to the external load
C. from the reverse biased diode D. in the same direction
41. The conduction band is closest to the valence band in
A. semiconductors B. conductors
C. insulators D. The distance is the same for all of the above.

42. What is the percent of regulation if Vnl = 20 V and Vfl = 19.8 V?

A. 0% B. 1% C. 0.1% D. 5%
43. Providing a constant output regardless of ac input or load resistance changes is the function of a:
A. transformer B. filter C. regulator D. rectifier
44. List three diode packages:
A. clip package, DIP, small current package
B. DIP, small current package, large current package
C. small current package, large current package, and SIP
D. small current package, large current package, clip package

45. If you drop a 5 when rounding a number, you are using the
A. round-to-even rule B. significant digit rule
C. round-off rule D. retained digit rule
46. When using the terms "accuracy" and "precision" for measurements
A. "precision" implies less measurement error than "accuracy"
B. "accuracy" implies less measurement error than "precision"
C. "precision" measures the repeatability of a measurement
D. both terms mean the same thing
47. The digits in a measured number that are known to be correct are called
A. accuracy digits B. significant digits C. error digits D. precision digits
48. Pico is what relation to micro?
A. one-tenth B. one-hundredth C. one-thousandth D. one-millionth
49. What is the flux density of a magnetic field whose flux is 3000 µWb and cross-sectional area is 0.25 m2?
A. 12,000 uT B. 83,330 T C. 0 T D. More information is needed in order to find flux density.
50. A Hall effect sensor
A. exists only in theory B. is a noncontacting magnetic sensor
C. can operate only a few times before failure D. produces very large voltages
51. What is the reluctance of a material that has a length of 0.045 m, a cross-sectional area of 0.015 m2, and a
permeability of 2500 µWb/At·m?
A. 833.33 µAt/Wb B. 0.27 At/Wb
C. 1200 At/Wb D. More information is needed in order to find the reluctance.
52. Which electromagnetic device has a movable iron core called a plunger?
A. A speaker B. A dc generator C. A relay D. A solenoid
53. What Power that is measured in volt-amperes is called
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A. impedance power B. reactive power C. true power D. apparent power
54. Calculate the magnitude of the impedance in the given circuit.
A. 24.1 M B. 10 M C. 26.1 M D. 0
55. What is the effect of increasing the resistance in a series RC circuit?
A. There will be no effect at all. B. The current will increase.
C. The phase shift will decrease. D. The input voltage will increase.
56. Increasing the number of turns of wire on the secondary of a transformer will
A. increase the secondary current B. decrease the secondary current
C. have no effect on the secondary current D. increase the primary current
57. What is the secondary voltage in the given circuit?
A. 13.3 V rms in phase with the primary B. 120 V rms in phase with the primary
C. 13.3 V rms out of phase with the primary D. 120 V rms out of phase with the primary
58. If the primary power of an ideal transformer having a 2:1 voltage ratio is 100 W, the secondary power is
A. 100 W B. 50 W C. 75 W D. 200 W
59. The capacitor that produces an ac ground is called a(n)
A. coupling capacitor B. dc open C. bypass capacitor D. ac open
60. Three different points are shown on a dc load line. The upper point represents the
A. minimum current gain B. quiescent point C. saturation point D. cutoff point
61. In order for feedback oscillators to have any practical value, the gain has to be
A. < 1 B. self-adjusting C. stabilized D. nonlinear
62. This circuit is a setup for
A. a current-to-voltage amplifier B. a constant-current source
C. an instrumentation amplifier D. an isolation amplifier
63. An instrumentation amplifier has a high
A. output impedance B. power gain C. CMRR D. supply voltage
64. In the classic three-op-amp instrumentation amplifier, the differential voltage gain is usually produced by
A. first stage B. second stage C. mismatched resistors D. output op-amp
65. How do fixed resistors usually fail?
A. slowly over time B. by increasing their value
C. by becoming an open circuit D. by increasing their value and becoming an open circuit
66. What resistor type is found in SIPs and DIPs?
A. metal film B. wirewound C. metal oxide D. thick film
67. The six basic forms of energy are:
A. light, sun, magnetic, chemical, electrical, and mechanical
B. electrical, mechanical, light, heat, magnetic, and chemical
C. electrical, mechanical, sun, heat, chemical, and light
D. potential, sun, light, chemical, electrical, and mechanical
68. A potentiometer has how many leads?
A. 1 B. 2 C. 3 D. 4
69. A color code of orange, orange, orange is for what ohmic value?
A. 22 kilohms B. 3300 ohms C. 44000 ohms D. 33 kilohms
70. What type of resistors have a tolerance rating of 5% or greater?
A. precision B. SIP C. general-purpose D. wirewound
71. What are the parts of a rheostat?
A. wiper and resistor track B. solenoid and armature C. contact and wire wound D. center tape and wiper
72. Electrical equipment is protected against excessive current by a(n):
A. fusible wire link B. insulated glass container C. metal ended coil D. circuit opener
73. One advantage of a carbon film resistor over a carbon composition resistor is:
A. less circuit noise B. smaller size C. higher wattage D. poor tolerance
74. If a metallic conductor has a positive temperature coefficient of resistance, then:
A. as temperature increases, resistance decreases B. as current increases, resistance decreases
C. as voltage increases, current increases D. as temperature increases, resistance increases
75. Wirewound resistors are usually used in circuits that have:
A. high current B. negative temperature coefficients C. low power D. high voltage
76. Good insulators:
A. have few electrons in their outer shells B. have a large dielectric strength
C. have a small breakdown voltage D. have many electrons in the nucleus
77. What is the most significant development in electronics since World War II?
A. the development of color TV B. the development of the diode
C. the development of the transistor D. the development of the TRIAC
78. Which material may also be considered a semiconductor element?
A. carbon B. ceramic C. mica D. argon
79. Which semiconductor material is made from coal ash?
A. germanium B. silicon C. tin D. carbon
80. When and who discovered that more than one transistor could be constructed on a single piece of
semiconductor material:
A. 1949, William Schockley B. 1955, Walter Bratten C. 1959, Robert Noyce D. 1960, John Bardeen
81. If conductance increases as temperature increases, this is known as a:
A. positive coefficient B. negative current flow C. negative coefficient D. positive resistance
82. What electrical characteristic of intrinsic semiconductor material is controlled by the addition of
impurities?
A. conductivity B. resistance C. power D. all of the above
83. A "U" shaped, opposite-polarity material built near a JFET-channel center is called the:
A. gate B. block C. drain D. heat sink
84. In the constant-current region, how will the IDS change in an n-channel JFET?
A. As VGS decreases ID decreases. B. As VGS increases ID increases.
C. As VGS decreases ID remains constant. D. As VGS increases ID remains constant.
85. With a 30-volt VDD, and an 8-kilohm drain resistor, what is the E-MOSFET Q point voltage, with ID = 3 mA?
A. 6 V B. 10 V C. 24 V D. 30 V

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86. When is a vertical channel E-MOSFET used?
A. for high frequencies B. for high voltages
C. for high currents D. for high resistances
87. How will a D-MOSFET input impedance change with signal frequency?
A. As frequency increases input impedance increases.
B. As frequency increases input impedance is constant.
C. As frequency decreases input impedance increases.
D. As frequency decreases input impedance is constant.

88. Using voltage-divider biasing, what is the voltage at the gate VGS?
A. 5.2 V B. 4.2 V
C. 3.2 V D. 2.2 V
89. In an n-channel JFET, what will happen at the pinch-off voltage?
A. the value of VDS at which further increases in VDS will cause no further increase in ID
B. the value of VGS at which further decreases in VGS will cause no further increases in ID
C. the value of VDG at which further decreases in VDG will cause no further increases in ID
D. the value of VDS at which further increases in VGS will cause no further increases in ID
90. A data conversion system may be used to interface a digital computer system to:
A. an analog output device B. a digital output device C. an analog input device D. a digital printer
91. How many NAND circuits are contained in a 7400 NAND IC?
A. 1 B. 2 C. 4 D. 8
92. Exclusive-OR (XOR) logic gates can be constructed from what other logic gates?
A. OR gates only B. AND gates and NOT gates
C. AND gates, OR gates, and NOT gates D. OR gates and NOT gates
93. The range of a valid LOW input is:
A. 0.0 V to 0.4 V B. 0.4 V to 0.8 V C. 0.4 V to 1.8 V D. 0.4 V to 2.4 V
94. Which of the following summarizes the important features of emitter-coupled logic (ECL)?
A. negative voltage operation, high speed, and high power consumption
B. good noise immunity, negative logic, high frequency capability, low power dissipation, and short propagation
time
C. slow propagation time, high frequency response, low power consumption, and high output voltage swings
D. poor noise immunity, positive supply voltage operation, good low-frequency operation, and low power
95. A TTL totem pole circuit is designed so that the output transistors are:
A. always on together B. providing phase splitting
C. providing voltage regulation D. never on together
96. A logic probe is placed on the output of a gate and the display indicator is dim. A logic pulser is used on
each of the input terminals, but the output indication does not change. What is wrong?
A. The dim indication on the logic probe indicates that the supply voltage is probably low.
B. The output of the gate appears to be open.
C. The LOW indication is the result of a bad ground connection on the logic probe.
D. The gate is a tri-state device.
97. Which test equipment best allows a comparison between input and output signals?
A. an oscilloscope B. a logic probe C. a spectrum analyzer D. a multitrace oscilloscope
98. Which device would best aid in shorted track detection?
A. multimeter B. current tracer C. logic pulser D. oscilloscope
99. A basic S-R flip-flop can be constructed by cross-coupling which basic logic gates?
A. AND or OR gates B. XOR or XNOR gates C. NOR or NAND gates D. AND or NOR gates
100. What is the resolution of a digital-to-analog converter (DAC)?
A. It is the comparison between the actual output of the converter and its expected output.
B. It is the deviation between the ideal straight-line output and the actual output of the converter.
C. It is the smallest analog output change that can occur as a result of an increment in the digital input.
D. It is its ability to resolve between forward and reverse steps when sequenced over its entire range.

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