Electronic Science: Test Booklet No
Electronic Science: Test Booklet No
Electronic Science: Test Booklet No
1. (Signature)
Roll No.
(Name)
Roll No.
2. (Signature)
(Name)
J8 8 0 9
PAPERII
ELECTRONIC SCIENCE
Time : 1 hours]
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J8809
(In words)
P.T.O.
ELECTRONIC SCIENCE
PAPERII
Note :
1.
This paper contains fifty (50) objective-type questions, each question carrying
two (2) marks. Attempt all of them.
When the rms output voltage of the bridge fullwave rectifier is 20 V the PIV across the
diode is :
(A)
2.
(C)
40
(D)
31.42
5V
(B)
0.3 V
(C)
1V
(D)
0V
(B)
1
y 12
(C)
Z12
(D)
(A)
(C)
5.
19.3
For a two part reciprocal network, the output opencircuit voltage divided by the input
current is equal to :
(A)
4.
(B)
3.
28.2
2
2
(s 11)
(B)
(D)
s
2
(s 11)
2s
2
(s 11)2
2s
2
(s 21)2
a pulse
(B)
(C)
a spike
(D)
a ramp
J8809
h 12
6.
7.
Two ideal FETs each characterized by the parameters gm and rd are connected in
parallel. The composite FET is characterized by :
(A)
gm
2 and 2 rd
(B)
gm
(C)
r
2 g m and d 2
(D)
2 gm and 2 rd
three cells
(C)
sixteen cells
(D)
four cells
(B)
16
(C)
256
(D)
255
0000H
(B)
0008H
(C)
0010H
(D)
0018H
P0
(B)
P1
(C)
(D)
P3
P2
The FORTRAN statement X55/1013.0 * 15/5.0 * 2110 * 3 will compute the value of
X as :
(A)
12.
(B)
11.
eight cells
10.
9.
2rd
8.
2 and
48.5
(B)
48
(C)
34.5
(D)
35
(D)
%o
J8809
%x
(B)
%d
(C)
%f
P.T.O.
13.
In a given medium
(A)
14.
308
3608
(B)
2708
(C)
1808
(D)
908
50
(B)
66.66
(C)
150
(D)
100
2310 25
(B)
5310 25
(C)
5310 26
(D)
2310 26
100 V
(B)
50 V
(C)
500 V
(D)
2V
1.3 mm
(B)
0.633 mm
(C)
0.85 mm
(D)
1.0 mm
(C)
thermocouple
(D)
RTD
(C)
Proportional
(D)
PID
20.
(D)
19.
908
18.
(C)
Ten bit errors occur in two million transmitted bits. The bit error rate is :
(A)
17.
608
If the carrier of a 100 percent modulated AM wave is suppressed, the percentage power
saving will be :
(A)
16.
(B)
A lossless line of length 500 m has L510 mH/m and C50.1 pF/m at 1 MHz. The
electrical length of the line is :
(A)
15.
158
s
5 3 . The magnetic and electric fields are out of phase by :
thermistor
(B)
LVDT
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On-off
(B)
Integral
4
Questions 21 to 30 :
Codes :
21.
(A)
Both (A) and (R) are true and (R) is the correct explanation of (A)
(B)
Both (A) and (R) are true but (R) in not correct explanation of (A)
(C)
(D)
Assertion (A) : Silicon diodes are preferred to germanium diodes for high temperature
operation.
Reason (R) :
22.
Assertion (A) : In two part networks Y and Z parameters are interrelated and hence
need not be defined separately.
Reason (R) :
23.
555 provides variation in duty cycle from 0 to 100% and drive a TTL
load.
25.
Assertion (A) : Multivibrators with 555 are preferred over those with BJT and digital
ICs.
Reason (R) :
24.
J8809
P.T.O.
26.
27.
28.
31.
Assertion (A) : Modern optical communication systems use the 1.55 mm band.
Reason (R) :
30.
Assertion (A) : BPSK and QPSK modulation schemes increase the binary data rate
in a given bandwidth.
Reason (R) :
29.
Germaniun diode
(ii)
Silicon diode
(iii)
Schottky diode
(iv)
(iv)
(i)
(iii)
(ii)
(B)
(i)
(iii)
(ii)
(iv)
(C)
(ii)
(iv)
(iii)
(i)
(D)
(iv)
(ii)
(i)
(iii)
J8809
32.
Byte
(ii)
Bit
(iii)
Word
(iv)
Nibble
33.
(A)
(ii)
(i)
(iii)
(iv)
(B)
(iv)
(iii)
(ii)
(i)
(C)
(i)
(ii)
(iii)
(iv)
(D)
(iii)
(i)
(iv)
(ii)
Coaxial cable
(ii)
Metallic waveguide
(iii)
Optical fiber
(iv)
Twisted pair
(iii)
(ii)
(i)
(iv)
(B)
(ii)
(i)
(iii)
(iv)
(C)
(iv)
(i)
(ii)
(iii)
(D)
(iv)
(ii)
(iii)
(i)
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P.T.O.
34.
Microwaves
(ii)
X - rays
(iii)
Ultraviolet radiation
(iv)
Infrared radiation
35.
(A)
(i)
(iv)
(iii)
(ii)
(B)
(ii)
(iii)
(iv)
(i)
(C)
(iii)
(iv)
(ii)
(i)
(D)
(iv)
(iii)
(ii)
(i)
Class C
(ii)
Class A B
(iii)
Class A
(iv)
Class B
(ii)
(iii)
(iv)
(i)
(B)
(iv)
(iii)
(iv)
(i)
(C)
(iii)
(iv)
(ii)
(i)
(D)
(iii)
(ii)
(iv)
(i)
J8809
36.
Match List I with List II and select the correct answer using the codes given below
the lists :
ListI
ListII
(a)
MOSFET
(i)
Thermal runaway
(b)
Breakdown Diodes
(ii)
Isolation
(c)
IC Fabrication
(iii)
Gate Capacitance
(d)
Transistor
(iv)
Avalanche
Codes :
37.
(a)
(b)
(c)
(d)
(A)
(iii)
(iv)
(ii)
(i)
(B)
(iv)
(ii)
(i)
(iii)
(C)
(i)
(ii)
(iii)
(iv)
(D)
(ii)
(i)
(iv)
(iii)
Match the List I with List II and select the correct answer using the codes given
below the lists :
ListI
ListII
(a)
Thevenins Theorem
(i)
Transmission Line
(b)
(ii)
Voltage Source
(c)
Superposition Theorem
(iii)
S - plane
(d)
ABCD Parameters
(iv)
Linear Network
Codes :
(a)
(b)
(c)
(d)
(A)
(iv)
(i)
(iii)
(ii)
(B)
(i)
(ii)
(iii)
(iv)
(C)
(ii)
(iii)
(iv)
(i)
(D)
(iii)
(iv)
(ii)
(i)
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P.T.O.
38.
Match List I with List II and select the correct answer using the codes given below
the lists :
ListI
ListII
(a)
Differentiator
(i)
0.5 V / ms
(b)
Voltage Regulator
(ii)
Wave shaping
(c)
V to F convertor
(iii)
IC 7809
(d)
IC 741
(iv)
Codes :
39.
(a)
(b)
(c)
(d)
(A)
(iii)
(iv)
(ii)
(i)
(B)
(ii)
(iii)
(iv)
(i)
(C)
(iv)
(iii)
(i)
(ii)
(D)
(iii)
(i)
(ii)
(iv)
Match List I with List II and select the correct answer using the codes given below
the lists :
ListI
ListII
(a)
Counters
(i)
Totempole output
(b)
TTL logic
(ii)
Sequential logic
(c)
CMOS
(iii)
Fastest logic
(d)
ECL
(iv)
VDD/3
Codes :
(a)
(b)
(c)
(d)
(A)
(i)
(ii)
(iii)
(iv)
(B)
(iv)
(ii)
(iii)
(iv)
(C)
(iii)
(i)
(iv)
(ii)
(D)
(ii)
(i)
(iv)
(iii)
J8809
10
40.
Match List I with List II and select the correct answer using the codes given below
the lists :
ListI
ListII
(A)
IC 8279
(i)
Serial communication
(B)
IC 8251
(ii)
Timer counter
(C)
IC 8051
(iii)
Keyboard controller
(D)
IC 8155
(iv)
Codes :
41.
(a)
(b)
(c)
(d)
(A)
(i)
(iii)
(iv)
(ii)
(B)
(iii)
(i)
(iv)
(ii)
(C)
(ii)
(i)
(iii)
(iv)
(D)
(iv)
(i)
(ii)
(iii)
Match List I with List II and select the correct answer using the codes given below
the lists :
ListI
ListII
(a)
8 Characters
(i)
register
(b)
do while
(ii)
c variable
(c)
(iii)
executable program
(d)
Storage class
(iv)
Codes :
(a)
(b)
(c)
(d)
(A)
(ii)
(iv)
(iii)
(i)
(B)
(i)
(iii)
(iv)
(ii)
(C)
(iv)
(ii)
(i)
(iii)
(D)
(ii)
(i)
(iii)
(iv)
J8809
11
P.T.O.
42.
Match List I with List II and select the correct answer using the codes given below
the lists :
ListI
ListII
(a)
Klystron
(i)
Negative Resistance
(b)
Gunn Diode
(ii)
Detection
(c)
Magnetron
(iii)
Bunching
(d)
PIN Diode
(iv)
Microwave Oven
Codes :
43.
(a)
(b)
(c)
(d)
(A)
(i)
(ii)
(iv)
(iii)
(B)
(i)
(iv)
(ii)
(iii)
(C)
(iii)
(i)
(iv)
(ii)
(D)
(iv)
(ii)
(i)
(ii)
Match List I with List II and select the correct answer using the codes given below
the lists :
ListI
ListII
(a)
Amplitude Modulation
(i)
Frequency interleaving
(b)
Frequency Modulation
(ii)
Multiplexer
(c)
(iii)
(d)
Codes :
(a)
(b)
(c)
(d)
(A)
(iii)
(iv)
(ii)
(i)
(B)
(iv)
(iii)
(i)
(ii)
(C)
(iii)
(i)
(ii)
(iv)
(D)
(iv)
(iii)
(ii)
(i)
J8809
12
44.
Match List I with List II and select the correct answer using the codes given below
the lists :
ListI
ListII
(a)
Intermodal Dispersion
(i)
Photo diode
(b)
Intramodal Dispersion
(ii)
Laser
(c)
Responsivity
(iii)
Multimode Fiber
(d)
Quantum efficiency
(iv)
Codes :
45.
(a)
(b)
(c)
(d)
(A)
(iii)
(iv)
(ii)
(i)
(B)
(iii)
(iv)
(i)
(ii)
(C)
(i)
(ii)
(iii)
(iv)
(D)
(ii)
(iii)
(i)
(iv)
Match List I with List II and select the correct answer using the codes given below
the lists :
ListI
ListII
(a)
Digital Multimeter
(i)
Phase
(b)
Oscilloscope
(ii)
Temperature
(c)
Bridge
(iii)
4 digit
(d)
LM 35
(iv)
L or C
Codes :
(a)
(b)
(c)
(d)
(A)
(ii)
(iv)
(iii)
(i)
(B)
(iii)
(iv)
(ii)
(i)
(C)
(iii)
(i)
(iv)
(ii)
(D)
(iv)
(iii)
(i)
(ii)
J8809
13
P.T.O.
Read the passage below and answer the questions (46-50) that follow based on your
understanding of the passage :
The tunnel diode is a thin junction diode which under low forward bias conditions
exhibits negative resistance. Because of thin junction and short transit time, it lends to
microwave application. Tunnel diode oscillators were found to be unstable. However,
if a high Q cavity is loosely coupled to the diode, a highly stable oscillator is obtained
with relative independence to temperature and bias voltage. The application of the
tunnel diode was in microwave oscillations and negative resistance amplifier.
The diode voltage-current characteristics illustrate two important properties of
the tunnel diode, namely, (i) diode exhibits dynamic negative resistance which is useful
for oscillator and amplifier, (ii) negative resistance occurs when both the applied voltage
and resulting current are low. The tunnel diode is a relatively low power device. The
negative resistance is capable of significant power gain.
Tunnel diode amplifiers may be used through out the microwave range as moderate to
low noise preamplifiers in all kinds of receivers. Tunnel diode amplifiers are immune to
ambient radiation encountered in interplanetary space and hence, practicable for space
work.
Gunn discovered the transferred electron effect and this effect was found in Gallium
Arsenide and Indium Phosphide. Gunn diodes are used as low power oscillators in
microwave receivers. The higher power Gunn oscillators are used as power output
oscillators, which include police radars, CW Doppler radars and burglar alarms.
Gunn diodes are greatly superior to IMPATT diodes. Gunn diode amplifiers cannot
compete for power output and low noise with GaAs FET amplifiers at frequencies
below 30 GHz.
Step recovery diodes are junction diodes which can store energy in their capacitance
and then generate harmonics by releasing a pulse of current. These diodes are widely
employed in all microwave semiconductor devices. Such a diode is also called a
snap off varactor, which is a silicon or GaAs pn junction diode. Step recovery diodes
are used in amplifiers for low-level noise performance in the X band
46.
47.
Indicate which of the following diodes does not use negative resistance for operation.
(A)
Schottky diode
(B)
Gunn diode
(C)
IMPATT
(D)
Tunnel diode
Crystal diode
(B)
Schottky diode
(C)
Backward diode
(D)
PIN diode
J8809
14
48.
One of the following microwave diodes is suitable for low power oscillators only :
(A)
49.
50.
Tunnel
(B)
Avalanche
(C)
Gunn
(D)
IMPATT
For best low level noise performance in the X-band one of the following should be used :
(A)
a bipolar transistor
(B)
a Gunn diode
(C)
(D)
an IMPATT diode
Germanium
(B)
Gallium Arsenide
(C)
Silicon
(D)
-oOo-
J8809
15
P.T.O.
J8809
16