NPCIL 2019 Exam paper
SA/ST
CAT-I (Electrical)
Hiren channel
(Electrical knowledge bank)
Question
No. 21
Transmission
efficiency is the ratio of
A) Power
input/Power output B) Power
output/Power input
C) Power
input/Voltage drop D) Voltage
drop/Power output
Answer Key: B
Question
No. 22
What is the
purpose of earthing?
A) Safety
for human life/building/equipment
B) Over
voltage protection
C) Voltage
stabilisation
D) All of the options
Answer Key:
D
Question
No. 23
Which of the
following is NOT a transmission medium?
A) Coaxial cables B) Modems
C) Microwave
systems D) Telephone lines
Answer Key: B
Question
No. 24
The SI unit
of admittance is
A) Ohm B) Siemens
C) Farad D)
Henry
Answer Key:
B
Question
No. 25
Which of the
following is/are a doubly excited magnetic system? A) Reluctance motor B) Electromagnetic relay
C) Toroid coil D) Synchronous motor
Answer Key: D
Question
No. 26
A Wattmeter
is an instrument which consists of
A) Voltage
coil B) Current coil
C) Potential coil D) Current and Potential coil
Answer Key:
D
Question
No. 27
Which of the
following sources is associated with the radiant efficiency of luminosity?
A) Current B)
Temperature
C) Pressure D) Voltage
Answer Key:
B
Question
No. 28
When there
is a change in the strength of the current in a conductor, the change in flux
produced by that current establishes counter-EMF in the conductor and this is
known as
A) Self
induction B) Mutual induction
C) Magnetic
flux D) Magnetic flux density
Answer Key: A
Question
No. 29
Find the
farad equivalent of one micro-farad.
A) 10 farad B) 10 farad
C) 10 farad D) 10 farad
Answer Key:
A
Question
No. 30
The system
voltage that is defined as the RMS voltage between the conductors is also
called
A) RMS phase
voltage B) Peak phase voltage
C) Line-to-line
voltage D) Phase-to-phase
voltage
Answer Key:
C
Question
No. 31
Copper and
Bismuth are examples of
A) Paramagnetic
materials B) Diamagnetic
materials
C) Ferromagnetic
materials D) none of
the options
Answer Key:
B
Question
No. 32
The primary
purpose of a megger is to measure resistances whose values are in the range of
A) μΩ B) mΩ
C) kΩ
D) MΩ
Answer Key:
D
Question
No. 33
Which of the
following is a static device through which electrical power from one circuit is
transferred to other circuit at same frequency?
A) Transformer
B) Motor
C) Generator D) Alternator
Answer Key:
A
Question
No. 34
Which of the
following is the unit of illumination?
A) Radians B) Lux
C) Lumens D) Candela
Answer Key:
B
Question
No. 35
The maximum
AC voltage which can be applied safely across a diode in its non-conducting
state is called
A) Peak
forward voltage B) Peak inverse
voltage
C) Bias
voltage D) Supply
voltage
Answer Key: B
Question
No. 36
Energy
stored in an inductor is given by _____.
A) (LI)2 /2 B) L2
I/2
C) 1/LI D)
(1/2) LI 2
Answer Key:
D
Question
No. 37
Which of the
following causes hunting in a synchronous motor? A) When supply voltage
fluctuates B) When changes in load
C) When power factor is unity D) Motor is under loaded
Answer Key:
B
Question
No. 38
The Pitch
factor is the ratio of the voltage induced in a
A) Short
pitch coil to a full pitch coil
B) Full
pitch coil to a short pitch coil
C) Full
pitch winding to distributed winding
D) Concentrated
winding to distributed winding
Answer Key: A
Question
No. 39
Which of
these determines the voltage across the parallel branches of a circuit with
more than one voltage source and helps reduce the complexity of that electrical
circuit?
A) Reciprocity
theorem B) Norton's theorem
C) Compensation
theorem D) Millman's theorem
Answer Key:
D
Question
No. 40
Thevenin
equivalent circuit consists of
A) Voltage
source in series with an equivalent resistor
B) Voltage
source in parallel with an equivalent resistor
C) Current source
in parallel with an equivalent resistor
D) Current source in series with an equivalent
resistor
Answer Key:
A
Question
No. 41
In a
synchronous motor, the excitation to the field winding for which the induced
EMF becomes greater than applied voltage is called
A) Under-excitation
B) Critical excitation
C) Over-excitation
D) Normal excitation
Answer Key:
C
Question
No. 42
For
measuring high resistance, we should use which of the following? A) Kelvin's
double bridge B) Wheatstone
bridge
C) Megger D) Galvanometer
Answer Key:
C
Question
No. 43
The cost of
electrical energy generated is reduced when
A) The load
factor and diversity factor are high
B) The load
factor is high but diversity factor is low
C) The load
factor is low but diversity factor is high
D) The load
factor and diversity factor are low
Answer Key:
A
Question
No. 44
Which of the
following chemicals is used in the breather for transformer?
A) Asbestos fiber B) Silica sand
C) Sodium chloride D) Silica
gel
Answer Key:
D
Question
No. 45
______ Type
rotor is used for slow speed alternators which have large diameters and small
axial lengths.
A) Non-salient
pole B) Salient pole
C)
Cylindrical D) Smooth
cylindrical
Answer Key:
B
Question
No. 46
Excessive
luminances and/or excessive luminance ratios in the field of vision are
commonly referred to as
A) Uniform
lighting B) Glare
C) Colour D) Illumination
Answer Key:
B
Question
No. 47
According to
___________ the illumination at any point on a surface is proportional to the
cosine of the angle between the normal at that point and the direction of
luminous flux.
A) Lambert's
Cosine law B) Faraday's
law
C) Coulomb's
law D) Law of
cosines
Answer Key:
A
Question
No. 48
The value of
susceptibility in case of vacuum is taken as
A) Zero B) 0.5
C) Unity D) Infinity
Answer Key:
A
Question
No. 49
Capacitive
reactance of a capacitor ___________ as the frequency across its plates
increases.
A) Decreases B)
Increases
C) Equal D)
Zero
Answer Key:
A
Question
No. 50
Skin effect
exists only in
A) AC transmission B) DC transmission
C) AC/DC
D)None of
the above
Answer Key: A
Answer Key: A
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