| Post Name | Lr. IN ELECTRONICS ENGG. (Govt. Polytec. Colleges) - TECH. EDUN. |
|---|---|
| Question Paper Code | 004/2021 |
| Category Code | 019/2019 |
| Date of Test | 5 January 2021 |
| Medium of Question | ENGLISH |
| Exam Type | OMR Examination |
| Total Questions | 100 |
1
If lim as x → 2 of (xⁿ − 2ⁿ)/(x² − 4) = 20 and n is a positive integer, then n is:
Answer
B. 5
2
The slope of the normal to the curve y = 2x³ at the point whose x coordinate is 2 is:
Answer
B. −1/24
3
The value of the integral . 2 ex dx is
x
ex (x – 1) x ex
Answer
D. x +c
x
4
. e (1 + x) dx is
. sec (xex)
Answer
A. sin (xex) + c
5
The integrating factor of the differential equation dy/dx − y/x = sin x is
Answer
C. 1/x
6
A matrix X has a + b rows and b + 1 columns while the matrix Y has a − 2 rows and a + 2 columns. Both the matrices XY and YX exist. Then a and b are:
Answer
A. a = 5, b = 2
7
The value of the determinant 3 2 5 is 0, then k is
k 2 4
Answer
C. 2
8
If C0, C1, C2, …, Cn denote the coefficients in the bionomial expansion of (1 + x)n, then
C02 + C12 + … + Cn2 is
(2n)! 2n(n + 1)
Answer
A. @y
9
2 tan–1 (1) + tan–1 (2) + tan–1 (3) is
Answer
B. 4
10
The foot of the perpendicular from (2, 3) to the line 2x + y − 3 = 0 is:
Answer
D. (2/5, 11/5)
11
Which among the following is the correct method for designing the combined footing for
two column loads ?
Answer
C. Centre of gravity of column loads coincides with the centre of gravity of soil
reaction.
12
If using a Dumpy level and a levelling staff, a back sight is noted on a Bench mark of
reduced level 100 as 0.60 and fore sight is noted on a point A as 0.80, what is the reduced
level of point A ?
Answer
B. 99.80
13
What is a fine aggregate ?
Answer
B. Aggregate passing through 4.75 mm IS sieve and retained on 0.15 mm IS
sieve
14
What is the yield strength of plain bars (mild steel conforming to IS 432) ?
Answer
A. 250 N/mm2
15
In chain triangulation, what is the longest of main survey lines ?
Answer
D. Base line
004/2021 4 A
16
Compared to a four stroke engine of same size and rpm, a two stroke engine practically
produces
Answer
D. less than twice and greater than same power produced by the four stroke
engine
17
A flywheel is used to
Answer
B. decrease power fluctuations in the system
18
The functioning of a clutch can be improved by
Answer
A. providing liners with better coefficient of friction.
19
Function of surge tank in hydraulic power plant system is to
Answer
C. reduce water hammer effect and breakage of penstock during sudden open /
closure of valves.
20
The most hazardous among power plants of same rating is
Answer
D. Nuclear power plant.
A 5 004/2021
21
Two 230 V, 100 W bulbs are connected in series with 230 V supply. What will be the
power consumption of each bulb ?
Answer
D. 25 W
22
An electric iron is rated as 2000 W. If it is ON and OFF for equal durations while
ironing, how long will it take to consume one unit of energy ?
Answer
B. one hour
23
An inductor of 10 Ohms reactance and a capacitor of 10 Ohm reactance at 50 Hz are
connected in series with a 10 Ohm resistor. If the combination is connected to a 300 V,
50 Hz supply, the current will be
Answer
A. 30 A
24
Two resistors of 12 Ohm and 5 Ohm are connected in series and the combination is
connected in parallel with a 10 Ohm resistor. What will be the power consumed by the
10 Ohm resistor, if the network is connected to a 100 V supply ?
Answer
C. 1 kW
25
Buchholz relay is used in the protection of
Answer
D. transformer
26
If a single diode in a bridge rectifier opens, the dc value of output for an input of
Vm sin wt is
Vm
Answer
B.
2 Vm
27
A snubber circuit is used along with a relay for
Answer
C. avoid arcing
28
Which of the following devices is part of a microcontroller chip ?
Answer
D. All of these
29
GSM uses the following multiple access methods :
Answer
C. Combination of FDMA & TDMA
30
A standby UPS can be used for power requirements of
Answer
A. 0.5 kVA
31
In a zener diode with high breakdown voltage
Answer
Question Cancelled
32
Most of the holes present in the base of a PNP transistor flow
Answer
B. into the collector
33
A JFET configuration which connects a high resistance signal source to a low resistance
load is
Answer
Question Cancelled
34
When class B power amplifier is in a quiescent state, _____
Answer
C. no current flows through the transistor.
35
Inductor filter should be used when
Answer
A. load current is high
36
In a Wien-bridge oscillator, if the resistances in the positive feedback circuit are
decreased, the frequency _____.
Answer
C. increases
37
When frequency of oscillation of a crystal oscillator becomes parallel resonance
frequency, reactance of crystal oscillator becomes _____.
Answer
A. Infinity
38
The distortion in an amplifier is found to be 3%, when the feedback ratio of negative
feedback amplifier is 0.04. When the feedback is removed, the distortion becomes 15%.
Then the open loop gain
Answer
D. 100
39
Voltage gain of an amplifier without feedback is 60 dB. It decreases to 40 dB with
feedback. Then the feedback factor is _____
Answer
Question Cancelled
40
The switching of power with a PNP transistor is called _____.
Answer
C. sourcing current
41
In the initial stages of a multistage amplifier, we use _____.
Answer
A. RC coupling
42
The total gain of a multistage amplifier is less than the product of the gains of individual
stages due to _____.
Answer
B. loading effect of the next stage
43
The oscillator that is mostly used for generating audio frequency signals is
Answer
A. Wein bridge
44
_____ multivibrator is a square wave oscillator.
Answer
B. Astable
45
In a bistable multivibrator circuit, commutating capacitor is used to
Answer
C. increase the speed of response
46
A certain non-inverting amplifier has Ri of 2 kand Rf of 100 kThe closed loop
voltage gain is _____.
Answer
C. 51
47
In differential mode of op-amp, if output voltage is equal to the difference between
outputs of individual transistors, its amplitude will be _____ the amplitude of signal
voltage yielded at collector to ground.
Answer
A. twice
48
Common mode voltage gain of an op-amp is generally
Answer
C. <1
49
A 741 op-amp has a gain bandwidth product of 2 MHz. If a non-inverting amplifier using
this op-amp has a voltage gain of 40 dB, then its –3dB bandwidth is _____.
Answer
B. 20 kHz
50
What part of the characteristic curve of a diode is useful for log amplifiers ?
Answer
C. The log region between 0 V and 0.7 V
51
The main purpose of an instrumentation amplifier is to amplify _____ signals that are
riding on _____ common mode voltages.
Answer
B. small, large
52
The filter which provides a roll-off rate greater than – 20 /dB / decade / pole and are
useful when a rapid roll-off required is _____.
Answer
B. Chebyshev
53
555 timer basically consists of _____.
Answer
B. two comparators
54
The output voltage of phase detector is _____.
Answer
C. error voltage
55
In a non-linear op-amp circuit, the
Answer
D. op-amp may saturate
56
A Schmitt trigger has _____ feedback.
Answer
A. positive
57
In the locked state of PLL, the phase error between the input & output is _____.
Answer
C. minimum
58
For an integrating circuit to be effective, the RC product should be _____ the time period
of the input wave.
Answer
D. atleast 10 times greater than
A 9 004/2021
59
The decimal equivalent of (11011.01)2 is
Answer
C. (27.25)10
60
A device which converts BCD to seven segments is called _____.
Answer
B. Decoder
61
– – –
The simplification of the Boolean expression
Answer
B. 1
62
– –– –
The SOP form of
Answer
A. + C)
63
Data can be changed from special code to temporal code by using
Answer
Question Cancelled
64
The gates required to build a half adder are
Answer
C. EX-OR gate and AND gate
65
_____ logic family has low power dissipation and _____ has excellent noise immunity.
Answer
B. RTL, HTL
66
Why is a pull-up resistor needed when connecting TTL logic to CMOS logic ?
Answer
C. To increase the output HIGH voltage
67
A basic S-R flip-flop can be constructed by cross-coupling of which basic logic gates ?
Answer
C. NOR or NAND gates
68
The output F of the given digital logic circuit is
–
Answer
A. F = X YZ + XYZ
–
69
The flash type A/D converters are called as
Answer
D. parallel comparator A/D converter
70
In a microprocessor, the address of the next instruction to be executed is stored in
Answer
D. Program counter
71
Which of the following instruction is not valid ?
Answer
B. MOV DS, 5000 H
72
Computer memory which is used to store programs and data currently being processed by
CPU is
Answer
B. RAM
73
A system is said to be shift invariant only if _____.
Answer
A. a shift in the input signal also results in the corresponding shift in the output.
74
Atmospheric noise become less severe at frequencies
Answer
B. above 30 MHz
75
A 2 GHz carrier is DSB SC modulated by a low pass message signal with maximum
frequency of 1 MHz. The resultant signal is to be ideally sampled. The minimum
frequency of the sampling impulse train should be
Answer
D. 4 MHz
A 11 004/2021
76
A 1 MHz sinusoidal carrier is amplitude modulated by a symmetrical square wave of
period 100 sec. Which of the following frequencies will not be present in the modulated
signal ?
Answer
C. 1020 kHz
77
A super-heterodyne radio receiver with an intermediate frequency of 455 kHz is tuned to
a station operating at 2800 kHz. The associated image frequency is
Answer
A. 3710 kHz
78
In a BPSK signal detector, the local oscillator has a fixed phase error of 40º. This phase
error deteriorates the SNR at the output by a factor of
Answer
B. cos2 40º
79
Compression in PCM refers to relative compression of
Answer
C. higher signal amplitudes
80
The Fraunhofer field of an antenna varies with distance r as
Answer
A. 1/r
81
A transmission line is feeding 2 Watt of power to a horn antenna having a gain of 10 dB.
The antenna is matched to the transmission line. The total power radiated by the horn
antenna into the free – space is
Answer
Question Cancelled
82
The design of optimum equi ripple linear phase FIR filter uses _____.
Answer
B. Chebyshev approximation
83
Which mode of propagation is adopted in HF antennas ?
Answer
Question Cancelled
84
The bandwidth of the channel used in the hopset is called _____.
Answer
C. Instantaneous bandwidth
85
_____ of TDMA system is a measure of the percentage of transmitted data that contains
information as opposed to providing overhead for the access scheme.
Answer
D. Efficiency
86
If the length of the intrinsic region in IMPATT diode is 4 m and the carrier drfit
velocity are 107 cm/s, then the nominal frequency of the diode is
Answer
A. 12.5 GHz
87
A forward voltage can be applied to an SCR after its
Answer
B. gate recovery time
88
Peak inverse rating of a TRIAC is
Answer
D. not very significant due to the nature of its application
89
The load voltage of a chopper can be controlled by varying the
Answer
A. duty cycle
90
A single phase full bridge inverter can operate in the load commutation mode in case
load consist of
Answer
B. RLC underdamped
91
_____ is used for growing n-p-n hetero-junction phototransistor.
Answer
D. Liquid-phase epistaxis
92
The diode which emits a single wavelength coherent light is
Answer
C. Laser diode
93
Which material in CRT glows when high energetic electrons strike its surface ?
Answer
D. Phosphor
94
If a multimeter has a sensitivity of 500 per volt and reads 50 V full scale, its internal
resistance will be
Answer
B. 25 k
95
LCDs operate from a frequency ranges from _____.
Answer
C. 30 Hz to 60 Hz
96
The use of SMPS is normally limited to power levels around _____.
Answer
Question Cancelled
97
The rate effect in silicon controlled switch (SCS) is caused by
Answer
D. Transition capacitance
98
Choose the correct statement :
Answer
C. IGBTs have lower gate drive requirements
99
Photo voltaic devices in the form of thin films which absorb and convert the sun-light
into electricity is
Answer
A. Cadmium Telluroide
100
A light dependent resistor is basically a
Answer
D. variable resistor
______________
004/2021 14 A
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