NIELIT Technical Assistant_2016_march

Question 1
The thermionic emission current is given by
A
maxwell’s equation
B
Fermi-Dirac distribution
C
Langmuir child law
D
Richardson Dushman equation
       Data-Communication       Richardson-Dushman-equation
Question 2
Zener breakdown occurs
A
due to rupture of covalent bonds
B
due to thermally generated minority carriers
C
in lightly doped junctions
D
only in germanium diodes
       Data-Communication       Zener-breakdown
Question 3
Negative feedback in an amplifier
A
increase noise
B
reduce bandwidth
C
reduce gain
D
increase distortion
       Data-Communication       amplifier
Question 4
The gain of a bipolar transistor drops at high frequencies because of
A
early effect
B
parasitic inductive elements
C
high current in base
D
transistor capacitance
       Data-Communication       Bipolar-Transistor
Question 5
The main application of enhancement mode MOSFET is in
A
oscillator circuits
B
amplifier circuits
C
clipper circuit
D
switching circuits
       Data-Communication       MOSFET
Question 6
Transducer is a device which
A
amplifies a given electrical signal
B
transfer an electrical signal from one place to another
C
translates a physical parameter into suitable electrical quantity
D
changes the waveform of an electrical signal
       Data-Communication       Transducer
Question 7
The turn ratio of a transformer is 20:1. If a load of 40 ohm is connected across the secondary. What will be the effective resistance seen looking into the primary ?
A
800 ohm
B
4 k ohm
C
8 k ohm
D
16 k ohm
       Electronics       Data-Communication
Question 8
N-channel FETs are considered better than p-channel FETs because
A
they consume less power
B
they have high switching time
C
mobility of electrons is greater than that of holes
D
they consume less power
       Data-Communication       N-channel/p-channel-FETs
Question 9
In a 4-bit weighted resistor D/A converter, resistor value corresponding to LSB is 16 k ohm. The resistor value corresponding to MSB is
A
32 k ohm
B
15 k ohm
C
64 k ohm
D
2 k ohm
       Data-Communication       A/D-Converter
Question 10
In a digital circuit, the clock is a
A
Flip-clop
B
Inverter
C
Monostable multivibrator
D
Free running multivibrator
       Data-Communication       Multivibrator
Question 11
In which of the following codes the successive numbers differ in only one bit position ?
A
ASCII
B
Gray Code
C
Excess-3 Code
D
BCD
       Digital-Logic-Design       Number-Systems
Question 12
An instruction used to set the carry flag in a computer can be classified as
A
data transfer
B
arithmetic
C
logical
D
program control
       Computer-Organization       Flags
Question 13
In FM modulation pre-emphasis is done for
A
low frequency components
B
high frequency components
C
middle frequency components
D
all frequency components
       Data-Communication       FM-Signal
Question 14
When modulation index of AM wave is increased from 0.5 to 1, the transmitted power
A
increases by 25%
B
increases by 33.3%
C
increases by 50%
D
remains same
       Data-Communication       Waveform
Question 15
The electric flux and field intensity inside a conducting sphere is
A
Minimum
B
Maximum
C
Uniform
D
Zero
       Electronics       Data-Communication
Question 16
A waveguide behaves as
A
high pass filter
B
low pass filter
C
band pass filter
D
all pass filter
       Data-Communication       Waveform
Question 17
In a lossless RLC circuit the transient current is
A
sinusoidal
B
square wave
C
triangular wave
D
non-oscillating
       Data-Communication       Waveform
Question 18
In an ac circuit, the maximum and minimum values of power factor can be
A
10 and 1
B
1 and -1
C
1 and 0
D
Any positive value
       Data-Communication       A/D-Converter
Question 19
In a circuit containing a complex impedance, maximum power transfer takes place when load is
A
pure resistance
B
equal to complex impedance
C
conjugate complex of the circuit impedance
D
inductive
       Digital-Logic-Design       Complex-Impedance
Question 20
The effect of doping intrinsic semiconductor is to
A
Move the Fermi level away from the centre of forbidden band
B
Move the Fermi level towards the centre of forbidden band
C
Change the crystal structure of the semiconductor
D
To keep the Fermi level at the middle of the forbidden band
       Electronics       Data-Communication
Question 21
Field Effect Transistor has
A
Large input impedance
B
Large output impedance
C
Large power gain
D
Small voltage gain
Question 22
The binary addition of 1+1+1 is
A
111
B
10
C
110
D
11
       Digital-Logic-Design       Number-Systems
Question 23
In an RC coupled amplifier, the voltage gain
A
Remains almost constant over a range of frequencies
B
Always increases with frequency
C
Always decreases with frequency
D
Is independent of frequency
       Data-Communication       amplifier
Question 24
Which of the following will not decrease as a result of introduction of negative feedback
A
Instability
B
Bandwidth
C
Overall gain
D
Distortion
       Computer-Networks       Bandwidth
Question 25
To generate a 1 MHz signal, the most suitable oscillator is
A
Colpitt’s oscillator
B
Phase shift oscillator
C
Wien bridge oscillator
D
None of these
       Data-Communication       Colpitt’s-oscillator
Question 26
The XOR gate produces high output only when two inputs are
A
High
B
Low
C
Different
D
Equal
       Digital-Logic-Design       Logic-Gates
Question 27
In a microprocessor, the address of next instruction to be executed is stored in
A
Stack pointer
B
Address latch
C
Program counter
D
Any general purpose register
       Computer-Organization       Microprocessor
Question 28
The LED’s for their display require
A
A voltage of 1.2v and a current of 20 mA
B
A voltage of 20v and a current of 1.2 A
C
A voltage of 1.2v and current of 100 mA
D
A voltage of 10v and a current of 120 mA
       Computer-Graphics       LED
Question 29
Two equal voltages os same frequency applied to the X and Y plates of a CRD, produces a circle on the screen. The phase difference between the two voltages is
A
30o
B
90o
C
180o
D
0o
       Computer-Graphics       CRD
Question 30
Kirchoff’s laws are applicable to
A
d.c. circuits only
B
a.c. circuits only
C
both a.c. and d.c. circuits
D
none of the above
       Data-Communication       Kirchoff’s-laws
Question 31
The materials having low retentivity are suitable for making
A
Temporary magnets
B
Permanent magnets
C
Weak magnets
D
None of these
       Data-Communication       magnets
Question 32
A 50KW, 3-phase, 400V, 60H induction motor runs at 1140 rpm. The % slip will be
A
1%
B
3%
C
5%
D
24%
       Electronics       Data-Communication
Question 33
Which of the following device can be used for controlling the speed of a dc motor ?
A
Thyratron
B
Thyristor
C
Transistor
D
Thermistor
       Electronics       Data-Communication
Question 34
The impulse response of an RL circuit is a
A
Rising exponential function
B
Decaying exponential function
C
Step function
D
Parabolic function
       Electronics       Data-Communication
Question 35
When the speed at which a conductor is moved through a magnetic field is increased, the induced voltage
A
Increases
B
Decreases
C
Remains constant
D
Reaches zero
       Electronics       Data-Communication
Question 36
Which of the following is the fastest analog to digital converter
A
Flash ADC
B
Dual slope ADC
C
Successive approximation ADC
D
Counter type ADC
       Data-Communication       A/D-Converter
Question 37
Which of the following μP is a 8 bit processor ?
A
80286
B
8085
C
80386
D
8086
       Computer-Organization       Microprocessor
Question 38
The load factor is equal to
A
Average load/peak load
B
Peak load/average load
C
Average load/connected load
D
Average load/base load
       Computer-Networks       Load-factor
Question 39
Open circuit test on transformer is conducted to determine
A
Core losses
B
Copper Losses
C
Eddy Current losses
D
Hysteresis Losses
       Data-Communication       Transformer
Question 40
Form factor is defined as
A
peak value / rms value
B
rms value / average value
C
rms value / peak value
D
average value / rms value
       Computer-Networks       Form-factor
Question 41
Given relations R(w,x) and S(y,z), the result of
SELECT DISTINCT w, x
FROM R.S is guaranteed to be same as R, if
A
R has no duplicates and S is non-empty
B
R and S have no duplicates
C
S has no duplicates and R is non-empty
D
R and S have the same number of tuples
       Database-Management-System       SQL
Question 42
Assume transaction A holds a shared lock R. If transaction B also requests for a shared lock on R, it will
A
result in a deadlock situation
B
immediately be granted
C
immediately be rejected
D
be granted as soon as it is released by A
       Database-Management-System       Transactions
Question 43
If a variable can take only integral values from 0 to n, where n is a constant integer, then the variable can be represented as a bit-field whose width is the integral part of (the log in the answers are to the base 2)
A
log (n) + 1
B
log (n-1) + 1
C
log (n+1) + 1
D
none of the above
       C-Programming       Bit-Field
Question 44
Consider the function
find (int x, int y)
{return ((x < y) ? 0 : (x - y)) ; }
Let a, b be two non-negative integers. The call find {a, find(a, b)} can be used to find the
A
maximum of a, b
B
positive difference of a, b
C
sum of a, b
D
minimum of a, b
       Programming       Functions
Question 45
Concurrent processes are processes that
A
do not overlap in time
B
overlap in time
C
are executed by a processor at the same time
D
none of the above
       Operating-Systems       Process-Synchronization
Question 46
In a multi-user operating system, 20 requests are made to use a particular resource per hour, on an average. The probability that no requests are made in 45 minutes is
A
e −15
B
e −5
C
1 − e −5
D
1 − e −10
       Engineering-Mathematics       Probability
Question 47
An FSM can be a
A
of finite tape length, rewinding capability and unidirectional tape movement.
B
of finite tape length, without rewinding capability and unidirectional tape movement.
C
of finite tape length, without rewinding capability and bidirectional tape movement.
D
of finite tape length, rewinding capability and bidirectional tape movement.
       Theory-of-Computation       Finite-Automata
Question 48
The major difference between a Moore and a Mealy machine is that
A
the output of the former depends on the present state and the current input
B
the output of the former depends only on the present state
C
the output of the former depends only on the current input
D
none of the above
       Theory-of-Computation       Moore-and-Mealy-Machine
Question 49
Which of the following is not primitive recursive but computable ?
A
Carnot function
B
Riemann function
C
Bounded function
D
Ackermann function
       Algorithms       Ackermann-function
Question 50
Which of the following weights makes the complement operation easier in BCD form ?
A
8-4-2-1
B
Excess-3
C
2-4-2-1
D
3-2-1-0
       Digital-Logic-Design       Number-Systems
Question 51
Which of the following logic families is well suited for high-speed operation ?
A
TTL
B
ECL
C
MOS
D
CMOS
       Digital-Logic-Design       Logic-Families
Question 52
The total number of possible Boolean functions involving ‘n’ Boolean variables is
A
infinitely many
B
n​ n
C
n​ 2
D
none of the above
       Digital-Logic-Design       Boolean-Function
Question 53
Let a n a n−1 ...a 1 a 0 be the binary representation of an integer b . The integer b is divisible by 3 if
A
the number of one’s is divisible by 3
B
the number of one’s is divisible by 3, but not by 9
C
the number of zeroes is divisible by 3
D
the difference of alternate sum, i.e., ( a 0 + a 2 + . ..) − ( a 1 + a 2 + . ..) is divisible by 3
       Digital-Logic-Design       Number-Systems
Question 54
Which of the following is not a standard RS-232C signal ?
A
RTS
B
CTS
C
DSR
D
VDR
       Data-Communication       VDR
Question 55
Start and stop bits are used in serial communication for
A
error detection
B
error correction
C
synchronization
D
slowing down the communication
       Computer-Organization       Synchronous-and-asynchronous-Communication
Question 56
The coefficient of x 2 in the expansion of is
A
-405/16
B
405/16
C
405/128
D
None of the above
       Engineering-Mathematics       Combinatorics
Question 57
for
A
x ∈ { 1, 1 }
B
x ∈ { 0,− 1 }
C
x ∈ { 1,− 1 }
D
x ∈ { 0, 3 }
       Engineering-Mathematics       Linear-Algebra
Question 58
Evaluate
A
α 2 + β 2 + γ 2
B
α 2 β 2 γ 2+1
C
(α + β + γ + 1 )2
D
α 2 + β 2 + γ 2+1
       Engineering-Mathematics       Linear-Algebra
Question 59
Given y = ln(ln n mx),dy/dx = ?
A
nm /x ln mx
B
n /nx ln mx
C
n / x ln mx
D
m / nx ln mx
       Engineering-Mathematics       Calculus
Question 60
Given 2 x + 2 y = 2 x+y , dy/dx = ?
A
-2y-x
B
2 x (2 y +1)/2 y (2 x -1)
C
2 x (2 y -2)/2 y (2 x -1)
D
2 x (2 y -1)/2 y (2 x -1)
       Engineering-Mathematics       Calculus
Question 61
The line y = m x + c will be tangent to the ellipse x 2/ 9 + y 2 / 4 = 1 , if c is equal to
A
3 / m
B
√ 9m 2 + 4
C
√ 1 + m 2
D
√ 4m 2 + 9
       Engineering-Mathematics       Co-ordinate-Geometry
Question 62
The circle x 2 + y 2 + 2 ax + 1 = 0 (where a > 0 ) is ________.
A
tangent to the y-axis
B
does not meet the y-axis
C
intersects the y-axis
D
intersects both x-axis and y-axis
       Engineering-Mathematics       Co-ordinate-Geometry
Question 63
A
B
C
D
       Engineering-Mathematics       Calculus
Question 64
A
1
B
1/2
C
-1
D
2
       Engineering-Mathematics       Calculus
Question 65
A
e 10
B
e -10
C
e 2
D
e 1/2
       Engineering-Mathematics       Calculus
Question 66
A
8/9
B
-8/9
C
-9/8
D
9/8
       Engineering-Mathematics       Calculus
Question 67
AB is a vertical pole. The end A is on the level ground, C is the middle point of AB and P is a point on the level ground. The portion CB subtends an angle β at P. If AP = nAB, then
A
tan β = (n+1)/(2n2+1)
B
tan β = n/(2n2+1)
C
t an β = (n-1)/(2n2+1)
D
tan β = n / (n2+1)
       Electronics       Data-Communication
Question 68
There exist positive integers A, B and C, with no common factor greater than 1, such that, Alog 200 (5) + B log 200 (2) = C then what is the value of A + B + C ?
A
6
B
7
C
8
D
9
       Electronics       Data-Communication
Question 69
Let and are unit vectors inclined at an angle α to each other. Then, if
A
2π / 3 < α < π
B
α = 5π / 12
C
α = 5π / 3
D
α = 4π / 3
       Engineering-Mathematics       Vectors
Question 70
A
-π / 2
B
2 / π
C
π / 2
D
-2 / π
       Engineering-Mathematics       Calculus
Question 71
The solution of the differential equation (dy / dx) + (y + x) = x 2 with y = 1 when x = 1 is
A
x y = x 4 + 2
B
2 x y = x 4 + 4
C
3 x y = x 4 + 4
D
4 x y = x 4 + 3
       Engineering-Mathematics       Calculus
Question 72
The perpendicular from the origin to the line y = m x + c meets it at the point ( − 1 , 2 ) . Then, the values of m and c are
A
m = 3/2 , c = 5/2
B
m = -1/2 , c = 5/2
C
m = 1/2 , c = -5/2
D
m = 1/2 , c = 5/2
       Engineering-Mathematics       Co-ordinate-Geometry
Question 73
Find the odd-man out:
A
DGJ
B
LOR
C
TWZ
D
PRU
       Reasoning       Alphabetical-Series
Question 74
Find the odd-man out:
A
belt
B
bow
C
socks
D
tie
       Reasoning       Anology
Question 75
Find the odd-man out:
A
axe
B
spade
C
club
D
heart
       Reasoning       Anology
Question 76
Complete the series by choosing the appropriate missing term from the options given. 80, 10, 70, 15, 60, ?
A
20
B
25
C
30
D
50
       Reasoning       Number-Series
Question 77
Complete the series by choosing the appropriate missing term from the options given. 664, 332, 340, 170, ?, 89
A
85
B
97
C
109
D
178
       Reasoning       Number-Series
Question 78
Complete the series by choosing the appropriate missing term from the options given. QPO NML KJI ? EDC
A
HGF
B
CAB
C
JKL
D
GHI
       Reasoning       Alphabetical-Series
Question 79
Complete the series by choosing the appropriate missing term from the options given. U32, V29, ?, X23, Y20.
A
W26
B
W17
C
Z17
D
X26
       Reasoning       Alpha-Number-Series
Question 80
Select the related letter/word/number/figure from the given alternatives. Book : Publisher :: Film : ?
A
Writer
B
Editor
C
Director
D
Producer
       Reasoning       Anology
Question 81
Select the related letter/word/number/figure from the given alternatives. Menu : Food :: Catalogue : ?
A
Books
B
Library
C
Newspaper
D
Rack
       Reasoning       Anology
Question 82
Select the related letter/word/number/figure from the given alternatives. Film : ADGH :: Milk : ?
A
ADGF
B
HDGE
C
HDGF
D
HEGF
       Reasoning       Anology
Question 83
Choose the most appropriate option. One-sixth of a certain number is four more than one-twelfth the number. Find the number.
A
6
B
18
C
36
D
48
       Aptitude       Ratios
Question 84
Choose the most appropriate option. Six less than (1/9)​th​ of 45 is
A
-1
B
-2
C
1
D
3
       Aptitude       Numerical
Question 85
Choose the most appropriate option. Twelve times one-half of a number is thirty six. What is the number?
A
3
B
6
C
8
D
18
       Aptitude       Numerical
There are 85 questions to complete.