| Post Name | SUB ENGINEER (ELECTRICAL) - KERALA STATE ELECTRICITY BOARD Ltd |
|---|---|
| Question Paper Code | 013/2023 |
| Category Code | 553/2021 |
| Date of Test | 10 February 2023 |
| Medium of Question | ENGLISH |
| Exam Type | OMR Examination |
| Total Questions | 100 |
1
Which of the following statements are TRUE about the resistance of a material?
(i) Resistance varies directly as its area of cross section
(ii) Resistance varies inversely as the length of the material
(iii) Resistance does not depend on the nature of the material
(iv) Resistance depends on the temperature of the material
Answer
D. (iv) only
2
Which of the following is NOT a good conductor of electricity?
Answer
C. Pure mineral oil
3
The output of a Schmitt trigger will be triangular if the input is square wave.
Which of these statements are correct?
Answer
A. 1, 2 and 3
4
Two wires A and B have the same cross section and are made of the same material.
Resistance of A is 600 Ξ© and Resistance of B is 200 Ξ© . The number of times of A is longer
than B is:
Answer
A. 3
5
If two identical 4A, 2 Ξ© Norton equivalent circuits are connected in parallel with like polarity
to like, the combined Norton equivalent circuit is:
Answer
C. 8A, 1 Ξ©
6
The Superposition theorem is essentially based on the concept of:
Answer
B. Linearity
7
One Kilowatt hour of electrical energy equals:
Answer
D. 860 Kilo-calorie
A 3
8
Two similar electric charges of 1 Coulomb each are placed 1 meter apart in air. Force of
repulsion between them would be nearly:
Answer
B. 9 Γ 10 9 N
9
If a dielectric slab of thickness 6 mm and Ξ΅α΅£ = 5 is inserted between the plates of an air capacitor with plate separation 8 mm, its capacitance is
Answer
A. Increased
10
A capacitor that stores a charge of 0.2 Coulombs at 10 volts has a capacitance of:
Answer
B. 0.02 Farad
11
Permeability in a magnetic circuit corresponds to ββββββββ in an Electric Circuit.
Answer
C. Conductivity
12
The lifting power of an electromagnet depends on:
Answer
D. Both
13
Which of the following instruments are equally accurate on dc as well as ac circuits?
Answer
A. Dynamometer wattmeter
14
Induction watt hour meters are free from:
Answer
D. Frequency error
15
The RMS value of a half wave rectified current is 5A, itβs value for full wave rectification
would be:
10 10
Answer
B. A
2 2
10 20
16
The reactance offered by a capacitor to alternating current of frequency 50 Hz is 20 Ξ© . If the
frequency is increased to 100 Hz reactance becomes:
Answer
C. 10 Ξ©
17
Which of the following is NOT considered a fixed cost while calculating the cost of electric
power generation?
Answer
Question Cancelled
18
If power factor is unity, the reactive power is:
Answer
C. Zero
19
In a series RLC circuit, R = 100 Ξ©, X_L = 300 Ξ©, X_C = 200 Ξ©. The phase angle of the circuit is:
Answer
B. 45Β°
20
In an ac circuit, the ratio of KW/KVA represents:
Answer
A. Power factor
21
Speed/time curve for electric trains for city service does not have:
Answer
B. Free running period
22
While considering train movement crest speed is the:
Answer
A. Maximum speed attained by a train during the run
23
Magnetic materials are heated with the help of:
Answer
D. Hysteresis loss
A 5 013/2023
24
During regenerative braking of electric motors:
Answer
D. They are made to run as generators
25
The advantage of corona effect in transmission line is that:
Answer
A. It works as a safety valve for electrical surges
26
The sag of transmission line is least affected by:
Answer
D. Current passes through the conductor
27
An interconnector between two generating stations facilitates to:
Answer
B. Run them in parallel
28
The string efficiency of a suspension type insulator can be increased by:
Answer
D. Both
29
Volume of copper required for an ac transmission line is inversely proportional to:
Answer
D. Power factor
30
Sheaths are used in underground cables to:
Answer
B. Protects from moisture and gases
31
Which of the following expressions depicts the diversity factor?
Answer
C. Ratio of sum of individual maximum demands to the maximum demand on the
power station
32
Which of the following is NOT a Non Conventional energy source?
Answer
B. Natural gas
33
Which of the following methods is an electrical storage method of solar energy?
Answer
A. Inductor storage
34
Impedance relay is used for the protection of:
Answer
A. Medium transmission lines
35
On which of the following effects of electric current, a fuse operates?
Answer
C. Heating effect
36
Which of the following circuit breakers are most suitable for the voltage 765 KV?
Answer
C. SF6 circuit breakers
37
Deflection torque in a measuring instrument:
Answer
A. Opposes control torque
38
Due to phase error energy meter will read:
Answer
Question Cancelled
39
The scale of a ammeter is uniform. Its type is:
Answer
B. Permanent magnet moving coil
40
Which of the following bridge is used for the measurement of dielectric loss?
Answer
C. Schering bridge
41
In two β wattmeter method of power measurement, one of the wattmeter shows negative
reading when the load power factor angle is:
Answer
C. Greater than 60 ο―
42
The current through a 10 Ξ© resistance is I = 4 + 2β2 sin 314t A. This current is measured by a permanent-magnet moving-coil meter as
Answer
A. 4 A
43
Voltages Vβ = 5 sin Οt and Vβ = 10 sin Οt are connected to the X and Y terminals of a CRO respectively. What shape is seen?
Answer
D. A Straight Line
44
In a digital voltmeter, the oscillator frequency is 500 KHz. The ramp voltage falls from 8V to
V in 25ms. What is the number of pulses counted by the counter?
Answer
Question Cancelled
45
Hall effect transducers are used for measuring:
Answer
Question Cancelled
46
As per the recommendation of ISI the number of outlets are permitted in a power circuit:
Answer
C. 2 points
47
The SI unit of Luminance is:
Answer
C. Candela/m2
48
A source of light of 1000 Candelas is situated 5 m above a working surface. Calculate the
illuminance directly below the source in Lux:
Answer
D. 40
013/2023 8 A
49
A fluorescent tube can be operated on:
Answer
C. Both AC as well as DC
50
In which type of wiring vulcanized Indian rubber and polyvinyl chloride insulated wires are
used as conductor?
Answer
Question Cancelled
51
The loop earth wire shall be of size less than:
Answer
Question Cancelled
52
What is the maximum length of the flexible conduit in the motor installation?
Answer
A. Less than 1.25 m
53
The Armature resistance of a 4-Pole Wave wound DC machine is 0.08 Ξ© . If the armature is
rewound as Lap winding. What is the armature resistance?
Answer
D. 0.02 Ξ©
54
In three point starter, the overload release coil operate, if ββββββββ current
increases beyond set limit.
Answer
B. Armature
55
What is the shape of armature flux in DC machine due to armature reaction?
Answer
B. Saddle
56
A DC series motor is running at rated speed. If the field winding is short circuited then the
motor will
Answer
B. Run at dangerously high speed
57
A transformer is a
Answer
D. All of the above
A 9 013/2023
58
Which winding structure require more insulation?
Answer
C. Sandwiched winding
59
If the load power factor of transformer is 0.85 lagging, then its primary power factor is:
Answer
A. 0.8 lag
60
The ratio error of a current transformer mainly depends on:
Answer
Question Cancelled
61
Skewing of squirrel cage rotor bars does not eliminate:
Answer
A. Space harmonics
62
Slip ring induction motor has ββββββββ excitation current and ββββββββ full
load power factor as compared to squirrel cage induction motor.
Answer
D. Low, Low
63
The supply voltage to a induction motor is 192V instead of 240V. Determine reduction in
starting current in percentage:
Answer
D. 20%
64
Two identical alternators each are rated for 25 MVA, 11 KV having a sub transient reactance
of 10% are connected in parallel. The short circuit level at the bus bar is:
Answer
A. 500 MVA
65
In a synchronous generator ratio of short circuit current to open circuit voltage is:
Answer
C. Synchronous admittance
66
A Synchronous motor is said to be over excited when it is operated at ββββββββ power
factor.
Answer
B. Leading
67
Reluctance motor is basically:
Answer
D. Single phase synchronous motor
68
The step angle of the stepper motor is 5ο― . If the stepping frequency is 3600 pulses per second,
then the shaft speed will be:
Answer
A. 50 rps
69
When a UJT is used for triggering an SCR, the wave shape of the voltage obtained from the
UJT circuit is
Answer
D. Saw-tooth wave
70
TRIAC is
Answer
C. 3 terminal bi-directional switch
71
Choose the correct statement:
Answer
C. MOSFET is a voltage controlled device
72
An SCR is turned off by:
Answer
D. None of the above
73
The load voltage of a chopper can be controlled by varying the :
Answer
D. Duty cycle
74
Which of the device converts the AC supply of one frequency into an AC supply of a different
frequency?
Answer
C. Cycloconverter
75
The SMPS working is based on:
Answer
A. Chopper principle
76
One of the basic requirements of servo motor is that it must produce high torque at all:
Answer
B. Speeds
77
Register of microprocessor which keeps track of the execution of program and which contain
the memory address of next instruction to be executed is called:
Answer
B. Program counter
78
What is the size of RAM and ROM in 8051 microcontroller?
Answer
C. 128 byte RAM and 4 kB ROM
79
Which of the timer can operate in the 16 bit condition?
Answer
B. Timer 1
80
The programmable logic controller is classified into:
Answer
A. Two
81
Which of the following are the components of process automation?
Answer
D. All of the above
82
Distributed control system is ββββββββ system.
Answer
A. Computerized control
83
Which of the following is a correct statement?
Answer
C. Both
84
How many levels are present in Distributed Control System manufacturing?
Answer
C. 5
85
The band gap of Silicon at room temperature is:
Answer
C. 1.1 eV
86
The emitter of a transistor is generally heavily doped because it:
Answer
C. Has to supply the charge carriers
87
Ripple frequency of the output wave form of a full-wave rectifier when fed with a 50 Hz sine
wave is:
Answer
D. 100 Hz
88
A zener diode, when used in voltage stabilization circuits, it is biased in:
Answer
A. Reverse breakdown region
89
Regulator IC 7905 provides regulated output voltage equal to:
Answer
D. β 5 V
90
A network that shifts a waveform to a different DC level, without changing the appearance of
the applied signal:
Answer
B. Clamper
91
Which of the following multivibrator is called the flip-flop?
Answer
C. Bistable multivibrator
92
Following circuit is ββββββββ clipper.
Answer
B. Shunt positive
93
Two amplifiers are connected in series
Answer
C. ascaded). The first amplifier has a voltage gain of
12 and the second has a voltage gain of 15. Find the output ac signal if the input signal is
0.05 volt:
94
How many types of coupling methods are there in a single stage transistor amplifier?
Answer
Question Cancelled
95
Consider the following statements:
1. A schmitt trigger circuit can be emitter-coupled-bi-stable circuit.
2. Schmitt trigger circuit exhibits hysteresis phenomenon.
3. The output of a Schmitt trigger will be triangular if the input is square wave.
Which of these statements are correct?
Answer
C. land 2 only
96
Op-Amp performs which type of mathematical operations?
Answer
D. All of the above
97
What is the value is to be considered for a donβt care condition?
Answer
D. Either 0 or 1
98
In a J-K flip-flop, if J=K the resulting flip-flop is known as:
Answer
A. T flip-flop
99
Ripple counter also called:
Answer
C. Asynchronous counter
100
Based on how data is entered or shifted out, shift registers are classified into βββββββ
categories.
Answer
C. 4
Discussion
Ask a doubt or share a tip.
No comments yet β start the discussion.