Answer: (B)
Answer: (A)
3.
The radiative and non-radiative lifetimes of the minority carriers in the active
region of a double heterojunction LED are 60 ns and 100 ns respectively. The
internal quantum efficiency is given by:
(A)
60%
(B)
62.5%
(C)
37.5%
(D)
82.5%
Answer: (B)
4.
In a p type silicon sample, the whole concentration is 2.25 × 1015/cm3.
If the intrinsic carrier concentration is 1.5 × 1010/cm3,
the electron concentration is given by
(A)
Zero
(B)
1010/cm3
(C)
105/cm3
(D)
1.5 × 1025/cm3
Answer: (C)
5.
A signal m(f) = 5 sin (2π 100t) frequency modulates a carrier. The resulting FM
signal is
{10
cos (2π 105t) + 15 sin (2π 100 t)}. The approximate bandwidth of FM signal
is
(A)
0.1 kHz
(B)
1 kHz
(C)
3.2 kHz
(D)
4 kHz
Answer: (C)
6.
What is the octal equivalent of the binary number 11111001?
(A)
761
(B)
762
(C)
371
(D)
372
Answer: (C)
Answer: (D)
8.
The gauge factor of a resistance wire strain gauge is a measure ofwww.netugc.in
(A)
Sensitivity of the gauge
(B)
Resolution
(C)
Dynamic range of displacement measurement capability
(D)
Variable inductance
Answer: (A)
9.
In an LVDT, the two secondary wind map are connected in differential to obtain
(A)
Higher output voltage
(B)
an output voltage which is phase sensitive, i.e., the o/p voltage has a phase
which can lead up to a conclusion whether the displacement of the core took
place from right to left or from left to right.
(C)
In order to establish a null or the reference point for the replacement of the
core.
(D)
Both (B) and (C)
Answer: (D)
10.
Microprocessor is also known as CPU. What is CPU?
(A)
Control Processing Unit
(B)
Central Processing Unit
(C)
Central Progressing Unit
(D)
Control Progressing Unit
Answer: (B)
11.
If ‘i’ is a variable, i++ denotes
(A)
‘i’ is incremented twice
(B)
‘i’ is incremented once
(C)
‘i’ is replaced with i + 2
(D)
‘i’ is multiplied by 2
Answer: (B)
12.
For a SMF, following characteristic are given by
1.
0 ≤ v < 2.405
2.
v >> 2.405
3.
Core radius is less than 10 μm
4.
Attenuation is of the order of 1 dB/km
Which
of the following statement is true?
(A)
1 and 4 is correct.
(B)
2 and 3 is correct.
(C)
1 and 3 is correct.
(D)
3 and 4 is correct.
Answer: (C)
13.
In a directional coupler, the power is applied at port 1 and output is taken from
the port 2. For this following statements are given:
1.
Coupling coefficient is given by C = 10 log10 P1/ P4.
2.
Coupling coefficient is C = 10 log10 P4 /P1.
3.
Directivity is given by D = 10 log10 P4/ P3.
4.
Directivity is given by D = 10 log P2
/P1.
Which
of the following statement is true?
(A)
1 and 3 is correct.
(B)
2 and 3 is correct.
(C)
2 and 4 is correct.
(D)
1 and 4 is correct.
Answer: (A)
14.
An AM demodulator can be implemented with
1.
A linear multiplier followed by low pass filter.
2.
A linear multiplier followed by high-pass filter.
3.
A diode followed by low pass filter.
4.
A linear multiplier followed by band-stop filter.
Which
one of the following is correct?
(A)
1 only
(B)
3 only
(C)
1 and 3
(D)
4 only
Answer: (C)
15.
NAND Gate can also be represented by
1.
AND – invert Gate
2.
OR – Invert Gate
3.
Bubbled OR
4.
Bubbled AND
Which
of the following is correct?
(A)
1, 2 and 3
(B)
1 & 2
(C)
2 & 4
(D)
1 & 3
Answer: (D)
16.
In 8085 processor,
1.
AD0 – AD7 are treated as input as well as output signals.
2.
HLDA is an output signal.
3.
HOLD is an output signal.
4.
SOD is an output signal.
(A)
1, 2 and 3 are output signals.
(B)
2, 3 and 4 are output signals.
(C)
1, 2 and 4 are output signals.
(D)
1, 3 and 4 are output signals
Answer: (C)
17.
A variable type ‘char’ indicates the range and the no. of bytes.
1.
1 byte
2.
2 bytes
3.
–127 to + 128
4.
–128 to +127
(A)
1 & 3
(B)
2 & 3
(C)
1 & 4
(D)
2 & 4
Answer: (C)
18.
The hygrometer is an instrument used to measure
1.
Rainfall
2.
Altitude
3.
Relative humidity
4.
Temperature
Which
of the following is true?
(A)
1 and 2 is true.
(B)
1 and 4 is true.
(C)
3 is true.
(D)
3 and 4 is true
Answer: (C)
19.
Hall effect can be used to measure
1.
Conductivity of the charge carrier.
2.
Mobility of the charge carrier.
3.
The number of valence electrons per atom.
4.
Band gap of the material.www.netugc.in
Which
of the following is correct?
(A)
1 and 2 are true
(B)
2 and 3 are true
(C)
3 and 4 are true
(D)
1 and 4 are true
Answer: (A)
20.
In a JFET, the amplification factor μ, transconductance gm., and the
dynamic drain resistance (rd) are related as
(A)
μ = gm/ rd
(B)
μ = rd/ gm
(C)
μ = rd × gm
(D)
μ = gm ⋅ rd2
Answer: (C)
21.
Consider the following materials used for fabrication of Photonic Ics.
1.
Ga P
2.
In As
3.
Ga As
4.
Si
The
correct sequence of the ascending order in terms of band gap energies is
(A)
1, 4, 2 and 3
(B)
4, 1, 2 and 3
(C)
2, 3, 1 and 4
(D)
2, 4, 3 and 1
Answer: (D)
22.
Consider the following:
1.
Quantization
2.
Sampling
3.
Encoding
4.
Low-pass filter
The
correct sequence for converting a low pass analog signal to Digital signal is
(A)
4, 3, 1, 2
(B)
4, 1, 2, 3
(C)
4, 2, 1, 3
(D)
4, 3, 2, 1
Answer: (C)
23.
Consider the following circuit configurations:
1.
Common emitter
2.
Common base
3.
Emitter follower
4.
Emitter follower using Darlington pair
The
correct sequence in increasing order of the input resistances of these configurations
is
(A)
2, 1, 4, 3
(B)
1, 2, 4, 3
(C)
2, 1, 3, 4
(D)
1, 2, 3, 4
Answer: (C)
24.
8085 microprocessor has a flag register. The following flags are there, keep
them in the ascending order starting from LSB to MSB.
1.
Parity flag
2.
Zero flag
3.
Carry flag
4.
Sign flag
(A)
1, 2, 3 and 4
(B)
2, 4, 1 and 3
(C)
3, 2, 1 and 4
(D)
3, 1, 2 and 4
Answer: (D)
25.
The following logic families have their propagation delay. Arrange them from
lowest propagation delay to highest propagation delay.
1.
TTL (Standard)
2.
ECL
3.
Low power CMOS
4.
DTL
(A)
2, 1, 4 and 3
(B)
2, 4, 1 and 3
(C)
4, 2, 3 and 1
(D)
1, 2, 3 and 4
Answer: (A)
26.
Match List-I with List-II and select the correct answer using codes given below:
List
– I List
– II
(a)
Indirect band gap (i) Ga As
(b)
Direct band gap (ii)
Cavity
(c)
Laser diode (iii)
Spontaneous emission
(d)
LED (iv)
Si
Codes:
(a) (b)
(c) (d)
(A)
(ii) (i) (iii) (iv)
(B)
(iii) (iv) (i) (ii)
(C)
(i) (iv)
(ii) (iii)
(D)
(iv) (i) (ii) (iii)
Answer: (D)
27.
List – I List
– II
(a)
Poisson’s equation (i) ∇2V = O
(b)
Laplace equation (ii) φH.dl
= I
(c)
Ampere’s Law (iii) ∇⋅E
= ρυ/∈o
(d)
Divergence of the field (iv) ∇2V = – ρυ/∈
Codes:
(a)
(b) (c) (d)
(A)
(iv) (ii) (i) (iii)
(B)
(ii) (iii) (i) (iv)
(C)
(iv) (i) (ii) (iii)
(D)
(i) (iv)
(ii) (iii)
Answer: (C)
28.
List – I List
– II
(a)
Frequency Modulation (i)
Balanced Modulator
(b)
Double sideband suppressed carrier (ii)
Companding
(c)
PCM (iii)
Pre-emphasis and Deemphasis
(d)
AM (iv)
Envelope Detection
Codes:
(a)
(b) (c) (d)
(A)
(i) (ii)
(iii) (iv)
(B)
(iv) (iii) (ii) (i)
(C)
(iii) (i) (ii) (iv)
(D)
(ii) (iv) (i) (iii)
Answer: (C)
29.
List – I List
– II
(a)
Non-Weighted Code (i) 8421
(b)
Error-Detecting Code (ii) Gray Code
(c)
Weighted Code (iii)
Hamming Code
(d)
Error-Correcting (iv)
Parity Check
Codes:
(a)
(b) (c) (d)
(A)
(ii) (i) (iii) (iv)
(B)
(ii) (iv) (i) (iii)
(C)
(i) (ii)
(iii) (iv)
(D)
(i) (iii)
(iv) (ii)
Answer: (B)
30.
List – I List
– II
(Transducers)
(Measured Quantity)
(a)
Capacitive transducer (i)
Temperature
(b)
Thermocouple (ii) Power
(c)
Bourdon gauge (iii)
Displacement
(d)
Solar cell (iv)
Pressure
Codes:
(a)
(b) (c) (d)
(A)
(i) (iii)
(ii) (iv)
(B)
(iii) (i) (iv) (ii)
(C)
(ii) (iv) (i) (iii)
(D)
(iv) (i) (iii) (ii)
Answer: (B)
31.
List – I List
– II
(a)
Voltage regulated IC (i) Figure of
merit
(b)
Bistable multivibrator (ii) CMRR
(c)
OPAMP (iii)
Capture range and locking range
(d)
Phase Locked Loop (iv) flip-flop
Codes:www.netugc.in
(a)
(b) (c) (d)
(A)
(i) (iii)
(iv) (ii)
(B)
(i) (iv)
(ii) (iii)
(C)
(iv) (iii) (i) (ii)
(D)
(iii) (ii) (iv) (i)
Answer: (B)
32.
List – I List – II
(a)
ASK (i) Uses two frequencies, mark
and space.
(b)
FSK (ii) Baud rate is same as bit
rate.
(c)
BPSK (iii) On-off keying
(d)
QPSK (iv) Baud rate is half of bit
rate
Codes:
(a)
(b) (c) (d)
(A)
(iii) (i) (ii) (iv)
(B)
(ii) (iii) (i) (iv)
(C)
(iii) (ii) (i) (iv)
(D)
(i) (iv)
(ii) (iii)
Answer: (A)
33.
List – I List – II
(a)
if statement (i) case
(b)
do statement (ii) return
(c)
switch statement (iii) while
(d)
main statement (iv) else
Codes:
(a)
(b) (c) (d)
(A)
(iii) (iv) (ii) (i)
(B)
(iv) (iii) (ii) (i)
(C)
(iii) (i) (iv) (ii)
(D)
(iv) (iii) (i) (ii)
Answer: (D)
34.
List – I List
– II
(Amplifier
type) (Circuit/property)
(a)
RC coupling (i)
Higher voltage gain and impedance matching.
(b)
Inductive coupling (ii) Ability
to amplify dc and low frequency signal.
(c)
Transformer coupling (iii) Minimum
possible non-linear distortion
(d)
Direct coupling (iv) Low
collector supply voltages can be used.
Codes:
(a) (b)
(c) (d)
(A)
(iv) (i) (iii) (ii)
(B)
(iii) (iv) (i) (ii)
(C)
(i) (ii)
(iii) (iv)
(D)
(iv) (iii) (ii) (i)
Answer: (D)
35.
List – I List – II
(a)
assembler (i) executes
program line by line.
(b)
compiler (ii) creates
machine code.
(c)
interpreter (iii) finds
faults during execution.
(d)
debugger (iv) creates object
file.
Codes:
(a)
(b) (c) (d)
(A)
(iv) (iii) (i) (ii)
(B)
(ii) (i) (iv) (iii)
(C)
(ii) (iv) (i) (iii)
(D)
(iii) (iv) (i) (ii)
Answer: (B)
Directions:
Q. Nos. 36 to 45: The following items consist of two statements, one labelled
the
“Assertion”
(A) and other labelled the “Reason” (R). You are to examine these two
statements carefully and decide if the Assertion (A) and the Reason (R) are individually
true and if so, whether the Reason is a correct explanation of the Assertion.
Select your answers to these items using the codes given below and mark your
answer accordingly.
Codes:
(A)
Both (A) and (R) are true and (R) is the correct explanation of (A).
(B)
Both (A) and (R) are true, but (R) is not the correct explanation of (A).
(C)
(A) is true, but (R) is false.
(D)
(A) is false, but (R) is true.
36.
Assertion (A): A reflex klystron makes use of a single cavity.
Reason
(R): The single cavity performs the functions of buncher as well as catcher
cavity.
Answer: (A)
37.
Assertion (A): LP01 is basically HE11 mode.
Reason
(R): Linearly polarised modes are strongly guided modes, in which TE and TM
modes do not have identical propagation constants.
Answer: (C)
38.
Assertion (A): Combinational circuits have no memory, timing or feedback loop.
Reason
(R): The output of combinational circuit depends on their input and previous
output state.
Answer: (C)
39.
Assertion (A) Digital base band modulation is also referred to as TDM.
Reason
(R): Pulse analog modulation is first step in converting analog signal to Digital
Signal.
Answer: (D)
40.
Assertion (A): Under certain conditions, one gets peak response at high
frequency in transformer coupled amplifiers.
Reason
(R): High frequency model of transformer coupled amplifiers is a resonant
circuit.
Answer: (C)
41.
Assertion (A): At high temperatures, the avalanche breakdown voltage of zener diode
remains constant.www.netugc.in
Reason
(R): At high temperatures, mean free paths of electrons and holes are shorter,
therefore a larger field is required to cause ionization.
Answer: (C)
42.
Assertion (A): Piezoelectric transducers are not suitable for ultra-low
frequency vibration measurement.
Reason
(R): Piezoelectric materials have a high dielectric constant.
Answer: (A)
43.
Assertion (A): The contents of Random Access memory is a volatile in nature. As
soon as the power is removed to the IC, the contents are erased from the
memory.
Reason
(R): The contents of Read only Memory are a non-volatile in nature.
Answer: (B)
44.
Assertion (A): Logarithms are used to change a multiplication or division
problem into a simpler addition and subtraction problem.
Reason
(R): The Laplace transform enables the circuit analyst to convert the set of
integro differential equations describing a circuit to the complex frequency
domain.
Answer: (B)
45.
Assertion (A): char str[] = “paper” ‘str’ acts as a constant pointer to a
string.
Reason
(R): *P = “Paper” “P” acts as a pointer to a constant string.
Answer: (B)
Read the passage and answer the Question
Nos. 46 to 50 that follows based on your understanding of passage.
Power devices with pnpn layers such as
SCR, SCS and GTO belong to thyrister series. However UJT is also a member of this
group. The silicon controlled rectifier (SCR) is three terminal pnpn semiconductor
switching device, which is probably most important circuit element after the diode
and the transistor. An SCR can be used as a controlled switch to perform
various functions such as rectification inversion and regulation of power flow.
It is unidirectional power switch and being extensively used in switching ac
and dc. It has capability to control power as high as 10 MW. The frequency range
of its application has also been extended up to 50 kHz. SCR is a rectifier with
control action. The third element called gate enables the controlled rectification
gate is used to turn SCR ‘ON’ but not turn it ‘OFF’. SCR is made of Si because
it has to handle high power and high temperature.
There are many advantages of SCR as a
switch i.e. the switching speed is very high up to 109 operation per
second and it permits control over a large current (30- 100 A) in the load by
means of a small gate current of few mA. SCR has two states turn ON and turn
OFF state. There are two ways to turn ON (i) keep the gate open and made the
supply voltage equal to the break over voltage (ii) operate SCR with supply voltage
less than break over voltage. The general methods used for turning the SCR OFF
are (i) anode current interruption and (ii) force commutation. It is not
advisable to turn the SCR ‘ON’ with zero gate signals.
Some of the applications of SCR are motor
controls, relay controls, inverters, preventive circuits, regulated power
supply and phase control. Another pnpn device have characteristic similar to
that of SCR is SCS (Silicon Controlled Switch).
A device that can control ac power to the
load during the positive and negative cycle of input is called ‘triac’. It is basically
a diac with a gate terminal for bilateral turn ON. Gate Turn OFF (GTO) switch
is one more pnpn device which can be turned ON or OFF with cathode gate. Some application
of GTO is counters, pulse generators and multivibrators.
Light activated SCR (SASCR) is turned ON
by the light falling on the gate. It is used as a relay, optical light
controller, phase controller and motor control device.
46.
If the applied voltage is increased further when an SCR is forward biased, then
(A)
It becomes more forward biased.
(B)
It becomes more reverse biased.
(C)
It will come to ‘ON’ state.
(D)
It will come to ‘OFF’ state.
Answer: (C)
47.
The di/dt if an SCR in an ac voltage controller is high
if the load is
(A)
A pure inductance
(B)
An induction motor
(C)
A pure resistance
(D)
A combination of resistance and inductance.
Answer: (D)
48.
Triac can be considered as
(A)
Two SCRs connected in antiparallel with common gate.
(B)
Two SCRs connected in parallel with common gate.
(C)
Two Resisters connected in anti-parallel.
(D)
Two GTOs connected in parallel with common cathode gate.
Answer: (A)
49.
Forced commutation is employed when anode voltage iswww.netugc.in
(A)
AC
(B)
DC
(C)
Pulsating
(D)
Triangular
Answer: (B)
50.
Diac is
(A)
Two terminal bidirectional switch.
(B)
Two terminal Unilateral switch.
(C)
Three terminal bidirectional switch.
(D)
Three terminal unilateral switch.
Answer: (A)
