| Post Name | Foreman (Electrical), Assistant Manager (Electrical) etc - Industries & Commerce, The Kerala Ceramics Ltd etc |
|---|---|
| Question Paper Code | 075/2022 |
| Category Code | 134/2019, 322/2019, 132/2020, 329/2020, 476/2020 |
| Date of Test | 30 June 2022 |
| Medium of Question | ENGLISH |
| Exam Type | OMR Examination |
| Total Questions | 100 |
1
A dc voltage of 40 V is applied across series connected resistors 4 ο and 3 ο. Find the
current through 2 ο resistance if it is connected across 4 ο resistor.
Answer
A. 6.1 A
2
Maximum power transferred from source to load when its Theveninβs equivalent
resistance is ________ the load resistance.
Answer
C. equal to
3
Three resistors RAB, RBC and RCA are connected in delta whose values are in the ratio
1 : 2 : 4, then the ratio of its equivalent resistance in star (R
Answer
B. 2 : 1 : 4
4
The reactive power of a RLC circuit connected to an ac source is proportional to
Answer
D. Difference between energy stored in electrical field and magnetic field
5
The resonant frequency of a RLC series circuit is f0. If the values of parameters are
halved, then the resonant frequency is
Answer
D. 2f0
6
If the amplitude of the voltage applied to an R = 8 Ξ©, X_L = 6 Ξ© series circuit is 150 V, the current through the circuit is ________ A.
Answer
B. 10.6
7
Two coils A and B of same material are connected in parallel across the supply. Coil A
has diameter and length double that of coil B. The heat produced by the coil A is ______
that of coil B.
Answer
A. more than
8
The power factor of a RLC series circuit connected across 230 V, 50 Hz supply is 0.8. If
the capacitor is removed from the circuit, then the power factor becomes 0.625. What
will be the power factor if inductor is also removed from the circuit ?
Answer
D. None of these
9
A l οF capacitor is charged to 400 V. Find the value of voltage to which the capacitor is
discharged if 0.06 J energy is removed from the capacitor.
Answer
B. 200
10
The quality factor of a RC series circuit is ______ to power factor.
Answer
B. inversely proportional
11
The magnetic susceptibility of a paramagnetic material is _______.
Answer
A. less than one but positive
12
The self-inductance of coil A is LA and that of coil B is LB. By keeping mutual
inductance between the coils same, if the self-inductance of coil B is increased 4 times,
what will be the change in coupling co-efficient, K ?
Answer
A. Reduced by half
13
The two inductance coils A and B in series with the axis of one coil perpendicular to the
axis of the other, then the mutual inductance is
Answer
C. zero
14
Energy stored in an inductive coil is _______ to square of current.
Answer
C. directly proportional
15
A coil has a time constant of 2 second and an inductance of 4 H. If the coil is connected
to 40 V source, what will be the rate of rise of current in A/sec at the instant of switching ?
Answer
A. 10
16
The ratio of magnetization to magnetizing force is called
Answer
D. Magnetic susceptibility
17
The potential inside a charged hollow sphere is
Answer
C. Same as that on the surface
18
The area of hysteresis loop is a measure of
Answer
A. Energy loss per cycle
19
Faradayβs law of electromagnetic induction and Lenzβs law are summarized in the equation
Answer
C. e = βdΟ/dt
20
The magnetic field required to reduce the residual magnetization to zero is called
Answer
B. coercivity
21
Distribution transformers are designed for lower _______
Answer
A. iron losses
22
The mechanical characteristics of a dc motor is
Answer
D. torque versus speed
23
What will be the number of poles to get maximum speed for an alternator ?
Answer
C. 2
24
The starting torque of a three phase induction motor is directly proportional to
Answer
C. VΒ²
25
Carbon brushes are preferred over copper brushes in dc machines
Answer
A. Due to self-lubricating property
26
What will be the change in emf induced in a dc generator if flux is reduced by 20% and
speed is increased by 20% ?
Answer
D. 4% reduced
27
A dc motor connected to 220 V supply takes 60 A. The power developed in the armature
is maximum when the back emf is ______ V.
Answer
B. 110
28
If the primary current of transformer is twice the secondary current, then it is named
______ transformer.
Answer
D. Step up
29
The iron-silicon alloy core is used in a transformer to
Answer
Question Cancelled
30
The most economically used transformer connection is ______ for small current and high
voltage applications.
Answer
A. Star-star
31
The octal number 752.222 is equivalent to which of the following ?
Answer
B. [1EA.49]16
32
A 4 bit ripple counter and a 4 bit synchronous counter are made using flip flops having a
propagation delay of 10n seconds each. If the worst case delay in the ripple counter and
the synchronous counter be R and S respectively, then
Answer
B. R = 40ns, S = 10ns
33
Which combinational circuit is well-known for selecting a single input from multiple
inputs & guiding the binary information to output line ?
Answer
A. Data selector
34
How many NOT gates are required for the construction of a 4 to 1 multiplexer from the
followings ?
Answer
Question Cancelled
35
In the case of adder circuits the carry propagation can be expressed as
Answer
Question Cancelled
36
The design and architecture of an arithmetic and logic circuit is established on which
scheme ?
Answer
B. Combinational logic
37
The clock frequency of an 8085 microprocessor is 10 MHz and time required to execute
an instruction is 1.2 οsec, then the T states needed for executing the instruction is
Answer
D. 12
38
When two processors 1 and 2 executing the same instruction set and under identical
conditions then a same input program running on second processor takes 25% less time
but incurs 20% more clock cycles per instruction as compared to the program running on
first processor. If the clock frequency of first processor is 1 GHz, then the frequency of
second processor is
Answer
D. 1.6 GHz
39
In 8085 assembly language, a sequence of two registers that multiplies the content of DE
register pair by two and stores that result in HL register pair is
Answer
D. XCHG & DAD H
40
Find the resolution of a 10-bit analog to digital converter for an input range of 10 V.
Answer
B. 9.77 mV
41
With available head of 1 m to develop 1 HP power output from a hydroelectric power
plant, the speed at which the turbine will rotate is called
Answer
A. Specific speed
42
A moderator which is used in nuclear power plant to slow down the fast moving neutrons
should have
Answer
D. Low molecular weight
43
A conductor is composed of seven identical copper strands, each having a radius of 2 cm.
Then the self GMD of the conductor will be
Answer
C. 4.35 cm
44
A circuit breaker has interrupted the current at the instant when its value is 5 kA with
inductance 10 mH and capacitance l οF. What will be resistance value required for
resistance switching process ?
Answer
D. 50 ο
45
An over current relay of current rating 5 A and setting 150% is connected to a 200/5A
CT. Then the line current required to pick up the relay is
Answer
C. 300 A
46
The most appropriate way of mitigating the problem of interference between power line
and communication line is to
Answer
A. Transpose the power line
47
What will be the nature of fault if a power system is subjected to a fault which makes the
zero sequence component of actual current equal to zero ?
Answer
B. LL fault
48
Which of the following stability is increased with the use of high speed circuit breakers
in power system ?
Answer
C. Transient stability
49
A transmission line has 4 units of string insulators. The voltage across the bottom most
unit is 45% of the total voltage, then the string efficiency of the arrangement is
Answer
D. 55.55%
50
A single phase two conductor line separated at a distance 1.5 m apart with radius of 2 cm
each, produce a self-inductance of
Answer
A. 1.83 mH/kM
51
Class A commutation is also called ______.
Answer
A. Self commutation
52
The advantages of using freewheeling diode are
Answer
Question Cancelled
53
A step up chopper has an input voltage of 200 V. The conduction time of the thyristor is
300 οs and the output voltage is 600 V. If the pulse width is halved for constant
frequency operation, the new output voltage is
Answer
C. 300 V
54
Three SCRs are connected to form a series string. The voltage across these thyristors are
300 V, 250 V and 200 V respectively. If the current flowing through these thyristors are
5 A, 9 A and 11 A respectively, what will be the value of equalising resistance to be
connected across each SCRβs ?
Answer
C. 15 ο
55
Snubber circuits are used with thyristors to
Answer
B. Limit the rate of rise of voltage,
dt
di
56
If the latching current of a thyristor is 4 mA, then the minimum width of the gate pulse
required to properly turn on the thyristor shown in the circuit below is ______.
Answer
C. 4 οs
57
The peak inverse voltage of a single phase fullwave bridge rectifier is
Vm
Answer
B. Vm
ο°
2Vm
58
Op-amp has differential gain of 10,000 and CMMR of 100 dB. The common mode
voltage gain is
Answer
D. 0.1
59
Which is not a characteristic of an ideal op-amp ?
Answer
C. High output impedance
60
The output of an op-amp increase 8 V in 14 οs. The slew rate is
Answer
C. 0.57
61
Consider the block diagram of a control system shown in figure below.
The canonical form of the above block diagram is
+
R ~G,G4G;+G) g
Answer
B. (G; + G4)Hy β Hy |,
G; + Gy
+
R G,G4G,+G) g
62
In the above signal flow graph, there are _____ number of combinations of two non-
touching loops.
Answer
C. 4
63
A system produces an output , for a unit step input.
S(S2 + 5S + 4)
The nature of the response is
Answer
D. over damped
64
The peak time Tp = 3 second for a system to which unit step input is applied. The
damping frequency in radians/second is
Answer
B. 1.05
65
The positional error co-efficient is
Answer
A. 8
66
The open loop transfer function of a unity feedback control system is G(s) = 1/(sΒ² + 6s + 9). The closed loop transfer function will have poles at
Answer
C. β3 Β± 1j
67
In type β 1 system, the velocity lag error is
Answer
C. Inversely proportional to the gain constant.
68
Which of the following is true for Routhβs criterion ?
1. It gives an idea about absolute stability.
2. The degree of instability and means to avoid it is not indicated by Routhβs criterion.
3. Jt indicates the number and values of unstable roots.
Answer
A. Both1&2
69
The effects of adding poles and zeros can be determined quickly by
Answer
C. Root locus
70
The Nyquist plot is given as
The gain margin is
Answer
A. 3.33
71
The resistance of a moving coil voltmeter is 13500 ο. The moving coil has 150 turns and
is 4 cm long and 3 cm wide. The flux density in the air gap is 5.5 ο΄ 10β2 Wb /m2. Find
the deflection torque produced by 150 V.
Answer
A. 11 ο΄ 10β5 N-m
72
Which of the following is not an integrating instrument ?
Answer
D. Galvanometer
73
Calculate the shunt resistance required for converting a 2 mA meter with internal
resistance of 60 ο into 0-100 mA ammeter.
Answer
B. 1.22 ο
74
Fluid friction damping can be used for
Answer
B. vertically mounted instruments
75
The sensitivity of an oscilloscope depends on
Answer
A. gain of vertical amplifier
76
Power loss can be considerably reduced while testing energy meter by
Answer
C. phantom loading
77
Speed of rotation of Induction type energy meter can be controlled by
Answer
A. adjusting the position of braking magnet
78
The aquadag coating in CRO is used to collect
Answer
B. secondary emission electrons
79
The sweep generator of a CRO is used to produce
Answer
A. A sawtooth voltage for the horizontal deflection of electron beam.
80
A moving coil ammeter has a uniform scale with 100 divisions and gives full scale
reading of 10 A. The instrument can read upto 1/5 th of a scale division with a fair degree
of certainity. Determine the resolution of the instrument in amperes.
Answer
C. 0.02 A
81
Which of the following system has memory?
Answer
D. y(t) = x(t) + x(t β 1)
82
A signal has a spectrum ranging from 0 to 15 kHz is to be sampled to be converted to
discrete form. What is the minimum number of samples per second that must be taken to
ensure recovery ?
Answer
B. 30,000 samples /second
83
Determine the fundamental period of the signal x(n) = 10 cos(0.2Οn).
Answer
A. 10
84
A system is described by T[x(n)] = g(n) x(n).
Which of the following is correct for the system ?
Answer
C. Memoryless
85
Check the casuality and stability of the following system :
h(n) =
Answer
A. Non casual and BIBO stable
86
A necessary and sufficient condition for BIBO stability of a discrete-time LTI system is that
Answer
B. Magnitude of every root of its characteristic equation must be < 1
87
The system is linear if it is
Answer
C. additive and homogeneous
88
Aliasing occurs when
Answer
D. f_s < 2f_x
89
A signal x(t) = cos(3Οt) + 2 cos(10Οt) is ideally sampled. Find the maximum allowable interval between the samples.
Answer
C. 0.1 seconds
90
An anti-aliasing filter is a
Answer
B. Low pass filter
91
Which of the following is a passive transducer ?
Answer
A. Linear potentiometer
92
In LVDT, the secondary windings are connected in
Answer
D. Series opposition
93
Which of the following is a primary cell ?
Answer
A. Zinc Carbon dry cell
94
In series grouping of batteries, increase in the number of cells results in
Answer
Question Cancelled
95
Due to moisture content in soil, the earth resistance
Answer
C. decreases
96
The purpose of earthing is to
Answer
C. provide a low resistance path to earth
97
Which is the advantage of cleat wiring system ?
Answer
D. Easy to locate fault in wiring
98
Which wiring method provides the best mechanical protection ?
Answer
B. Metal conduit wiring
99
Candela is the unit of
Answer
C. Luminous intensity of a source
100
Which lamp shows stroboscopic effect ?
Answer
B. Fluorescent lamp
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