| Post Name | ENGINEERING ASSISTANT (ELECTRONICS)/OVERSEER GR.I (ELECTRONICS) |
|---|---|
| Question Paper Code | 009/2026 |
| Category Code | 578/2024 |
| Date of Test | 2 February 2026 |
| Medium of Question | ENGLISH |
| Exam Type | OMR Examination |
| Total Questions | 100 |
1
Which among the following semiconductor materials exhibits the highest breakdown
voltage in a PN junction diode for similar doping levels ?
Answer
D. GaN
2
The dynamic resistance of a forward-biased PN diode increases with
Answer
B. decreasing the dC bias current
3
Zener and Avalanche breakdown phenomena display opposite temperature coefficients
because
Answer
A. Zener breakdown has a negative temperature coefficient, while Avalanche
breakdown has a positive temperature coefficient
4
For semiconductor diodes, the barrier potential decreases by approximately
Answer
A. 2 mV for each °C rise in temperature
5
The average value of a half wave rectifier is
Answer
B. Vm/π
6
The switching time of an opto coupler decreases with
Answer
Question Cancelled
7
Which parameter in a solar cell ensures the maximum number of photons of light energy
reach the p-n junction ?
Answer
B. Anti Reflective Coating
8
Which material is most commonly used in Light Dependent Resistors (LDRs) due to
its high photosensitivity in the visible spectrum ?
Answer
A. Cadmium Sulphide
9
Poor voltage regulation in voltage doublers can be improved with
Answer
D. Using large value capacitors
10
The output current in a phototransistor depends on
Answer
C. light intensity
11
In a transistor amplifier circuit negative feedback __________ amplifier bandwidth.
Answer
B. Increases
12
Fixed biasing circuit R_B = 330 K ohm, R_C = 15.5 K ohm, V_CC = 12 V and I_C = 3 mA. Determine V_CE.
Answer
Question Cancelled
13
In transistor configuration how β of a transistor is related to its α ?
Answer
B. β = α / 1 – α
14
An RC coupled amplifier has a voltage gain of 100 in the frequency range of
500 – 20 KHz. Calculate gain in dB.
Answer
C. 40
15
Field Effect Transistor (FET) is a ________ device.
Answer
A. Voltage Control
16
Which of the following oscillator provides high accuracy of oscillation ?
Answer
D. Crystal Oscillator
17
Change in Gate to Source voltage of FET is 1 Volt and Change in drain current is 1.5 mA.
determine the magnitude of transconductance.
Answer
A. 1.5 mS
18
mOSFET’s have an important property that they can be used as
Answer
D. All of the above
19
When emitter terminal of a Unijunction Transistor (UJT) is open the resistance of the
base terminal is
Answer
B. Very high
20
VI Characteristics of a Unijunction Transistor (UJT), the region between the peak point
and valley point is called
Answer
C. Negative Resistance Region
21
Slew rate limits the op-amp’s performance at
Answer
C. High frequency
22
A Schmidt trigger circuit using an op-amp is mainly used for
Answer
B. Converting analog signals to digital pulses
23
In the functional block diagram of 555 timer, the discharge transistor is
Answer
B. NPN transistor connected to ground
24
In an op-amp differentiator circuit, the input element is
Answer
C. Capacitor
25
lm317 has how many pins ?
Answer
B. 3
26
The reference voltage (Vref) in a dAC is used to
Answer
A. Set the output voltage range
27
The output impedance of an ideal R − 2R ladder DAC is
Answer
A. R
28
The accuracy of ramp-type AdC mainly depends on
Answer
A. Clock frequency and ramp linearity
29
A higher number of bits in an AdC gives
Answer
B. Higher resolution
30
The conversion time of a successive approximation AdC depends on
Answer
C. Number of bits and clock frequency
31
Which impedance is defined as the impedance seen looking into the network with the
other end terminated by the same impedance ?
Answer
A. Iterative impedance
32
For symmetrical T networks, the characteristic impedance is
Answer
B. Geometric mean of open and short circuit impedances
33
Which of the following affects the characteristic impedance Z0 of a lossless
transmission line ?
Answer
B. Only inductance l and capacitance C
34
A constant resistance equalizer typically results in
Answer
B. Constant input impedance over frequency range
35
Which parameter is critical for designing attenuator resistor values in T and Pi networks ?
Answer
C. Characteristic impedance and attenuation level
36
What is the benefit of a Pi-pad attenuator over a T-pad attenuator ?
Answer
B. Better impedance matching at high frequencies
37
A filter designed to eliminate frequencies in a specific range while allowing others to
pass is called
Answer
B. Band-stop filter
38
Standing waves occur on a transmission line due to
Answer
B. Reflections caused by load mismatch
39
If SWR is greater than 1, it indicates
Answer
B. Presence of reflected wave leading to standing waves
40
Which waveguide type typically supports guided light waves at optical frequencies ?
Answer
Question Cancelled
41
Which of the following microphone works using the principle of capacitance variation
with sound ?
Answer
D. Condenser microphone
42
The diaphragm of a moving coil microphone converts
Answer
B. Sound pressure into mechanical movement
43
Which of the following is true about the diaphragm in a dynamic cone type
loudspeaker ?
I. made of paper, plastic or light metal.
II. Converts the motion of the voice coil into sound waves by vibrating air.
III. The narrow end
Answer
A. pex) of the cone is attached to the speaker frame.
44
Which of the following statements are true ?
I. diaphragm of woofer is larger than midrange.
II. Powerful bass sounds are produced by tweeter.
III. The crossover network divides the signal into three frequency bands.
Answer
D. I and III
45
Which of the following statements are true ?
I. Rotation speed of a Cd changes because it uses Constant linear Velocity.
II. A Cd uses a blue laser with wavelength of 700 nm.
III. CDs store digital data as tiny indentations (pits) and flat areas (lands) on the disc
surface.
IV. The laser used in a dVd player has a wavelength of about 650 nm.
Answer
Question Cancelled
46
What is the gain of antenna with directivity of 10 and efficiency of 0.8 ?
Answer
A. 8
47
Which of the following antenna that gives unidirectional radiation pattern ?
Answer
A. End-fire array antenna
48
Which of the following statements are false about a yagi-Uda antenna used as receiver ?
I. driven element is used to receive feed power.
II. director have a length equal to λ/2.
III. The parasitic elements in a yagi-Uda antenna are directly connected to the
transmission line.
Answer
B. II and III
49
What is skip distance in ionospheric propagation ?
Answer
B. minimum distance from transmitter where sky wave is received
50
What is the mUF if the critical frequency of the F2 layer is 5 mHz and the angle of
incidence is 60° ?
Answer
D. 10 mHz
51
Maximum transmission efficiency of amplitude modulation is
Answer
A. 33.33%
52
The disadvantages of using balanced slope detector for demodulation of Fm signal
Answer
C. Both
53
Am broadcast station transmits modulating frequency of 6 KHz. If carrier frequency is
820 KHz then frequency components in Am waves are
Answer
C. 820 KHz, 826 KHz, 814 KHz
54
The intermediate frequency of a superheterodyne receiver is 455 KHz. If it is tuned to
1500 KHz the image frequency will be
Answer
B. 2410 KHz
55
The function of Compander in Communication system
Answer
A. Equalize SNR for both weak and strong signals
56
A single tone 5 KHz message signal is sampled with 9 KHz, 7 KHz and 12 KHz. Aliasing
effect will be seen in the reconstructed signal when signal is sampled at
Answer
B. 7 KHz and 9 KHz
57
Indirect method of Fm generation
i. does not require the carrier oscillator to respond directly to the modulating signal.
ii. Use frequency multiplication.
iii. Generate stable Fm signal.
iv. It involves a crystal oscillator, a phase modulator and frequency multiplier.
Answer
D. All of the above (i, ii, iii and iv)
58
The disadvantages of frequency modulation over amplitude modulation are
Answer
Question Cancelled
59
A PAm signal can be detected using
Answer
B. Low pass filter
60
In Pulse Code modulation if the number of quantization level is increased from
16 to 256 then the bandwidth requirement will approximately be
Answer
A. 2 times
61
Which modulation scheme is used in transmitting sound in the monochrome television
transmission method ?
Answer
B. Fm
62
In a television transmission, which bandwidth-saving method is used in video
modulation ?
Answer
B. VSB
63
Colour-killer, kills the colour when
Answer
B. Colour burst signal is absent
64
Which stages of the colour TV receiver controls contrast and brightness ?
Answer
D. Luminance amplifier
65
Sound intermediate frequency in monochrome TV receivers in India is
Answer
C. 33.4 mHz
66
Blind speed problem in radar is avoided using
Answer
C. Vary the pulse repetition frequency
67
If the peak power of the radar is increased 16 times and other parameters are constant,
the range of the radar is
Answer
A. Increased by 2 times
68
Plan Position Indicator (PPI) displays
Answer
B. map of the target area
69
dispersion is
Answer
C. Separating light into each of its component frequencies
70
Which optical detector provides internal amplification using impact ionisation ?
Answer
C. Avalanche photo diode
71
In an ISDN Basic Rate Interface
Answer
B. RI), signalling information between the user and
network is managed through
72
The “Index of Cooperation (IOC)” in facsimile transmission relates to
Answer
Question Cancelled
73
Which recording method in a facsimile receiver gives high-quality reproduction and is
often used in commercial fax machines ?
Answer
Question Cancelled
74
A system transmits at a bit rate of 4 Mbps using raised cosine filtering with a roll-off
factor of 0.25. The required minimum transmission bandwidth is approximately
Answer
B. 2.5 mHz
75
If the number of symbols transmitted per second in a digital communication system is
increased while each symbol still represents the same number of bits, then
Answer
B. Both bit rate and baud rate increases
76
For the Assertion
Answer
A. and Reason
77
match the following digital codes with their descriptions :
Column A Column B
a. Baudot code 1. Text 7-bit code
b. ASCII 2. Error correction code
c. EBCdIC 3. Teleprinter 5-bit code
d. Hamming code 4. IBm 8-bit code
Code :
Answer
A. a – 3, b – 1, c – 4, d – 2
78
The minimum hamming distance required to correct two errors and detect three is
Answer
C. 5
79
In an ASK demodulator, the envelope detector primarily
Answer
B. Converts amplitude fluctuations into corresponding baseband signal
80
Which of the following correctly describes a synchronous modem ?
Answer
D. Both
81
Geostationary satellites are located approximately
Answer
B. 36000 kilometers above the earth
82
Kepler’s third law states that
Answer
D. The square of a planet’s orbital period is proportional to the cube of the length of
the semi major axis of its orbit
83
The orbit which is below 1000 kilometer distance from the sea level is called
Answer
C. Low Earth Orbit (LEO)
84
Closest distance of the satellite orbit to earth is
Answer
A. Perigee
85
Active satellites have
Answer
D. All of the above
86
The sub system in satellite communication responsible for collecting data from on-board
sensors to monitor the health and performance of a satellite is
Answer
C. Telemetry sub system
87
INTElSAT stands for
Answer
A. International Telecommunication Satellite
88
Geographical representation of satellite antenna radiation pattern is called
Answer
B. Foot print
89
Which of the following is a satellite earth station antenna ?
Answer
D. Cassagrain antenna
90
The unit which detects the satellite signal relayed from the feed and converts it to an
electric current, amplifies and lower its frequency is
Answer
B. lNA
91
A simplified cellular telephone system primarily aims to
Answer
B. Enable frequency reuse across cells
92
CdmA allows multiple users on the same frequency using
Answer
A. Unique codes
93
Roaming in cellular systems allows
Answer
B. Users to move between different networks
94
Improving coverage and capacity in cellular systems includes techniques like
Answer
C. Cell splitting and sectoring
95
In GSm, radio subsystem uses
Answer
D. Gaussian Minimum Shift Keying (GMSK)
96
For a cellular system with cluster size N = 7, if the total available channels are 395 and
each cell is allocated the same number of channels, how many channels are available
per cell ?
Answer
B. 56
97
The full form of GSm in the cellular service is
Answer
A. Global System for mobile Communications
98
In a hexagonal cellular system with a frequency reuse cluster size of 7, what is the
co-channel reuse ratio (Q) ?
Answer
C. 4.58
99
Which interference type is mitigated by proper channel assignment ?
Answer
C. Both
100
FdmA stands for
Answer
A. Frequency division multiple Access
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