Inspector of Factories • Paper-II
The power factor of a squirrel-cage induction motor is -
A)
low at light loads only
B)
low at heavy loads only
C)
low at light and heavy loads both
D)
low at rated load only
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'low at light loads only' (Option A).
Inspector of Factories • Paper-II
The use of high speed CB -
A)
reduces the short circuit current
B)
improves system stability
C)
decreases system stability
D)
increases the shorter circuit current
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'decreases system stability' (Option C).
Inspector of Factories • Paper-II
The term ‘cogging’ is associated with -
A)
three phase transformer
B)
compound generators
C)
D.C. series motor
D)
induction motors
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'induction motors' (Option D).
Inspector of Factories • Paper-II
Maximum efficiency of modern coal-fired steam-raising thermal power plants is restricted to about 0.35 (a low value), mainly because of -
A)
low alternator efficiency
B)
high energy loss in boilers
C)
low steam turbine mechanical efficiency
D)
high energy loss from turbine exhaust to condenser
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'high energy loss in boilers' (Option B).
Inspector of Factories • Paper-II
The efficiency and p.f. of a SCIM increases in proportion to its -
A)
speed
B)
mechanical torque
C)
voltage
D)
rotor torque
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'voltage' (Option C).
Inspector of Factories • Paper-II
For proper parallel operations, a.c. polyphase alternators must have the same -
A)
speed
B)
voltage rating
C)
kVA rating
D)
excitation
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'excitation' (Option D).
Inspector of Factories • Paper-II
In performing the short circuit test of a transformer -
A)
high voltage side is usually short circuited
B)
low voltage side is usually short circuited
C)
any side is short circuited with preference
D)
none of these
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'none of these' (Option D).
Inspector of Factories • Paper-II
The ‘crawling’ in an induction motor is caused by -
A)
high loads
B)
low voltage supply
C)
improper design of machine
D)
harmonics developed in the motor
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'harmonics developed in the motor' (Option D).
Inspector of Factories • Paper-II
In the HVDC system, the ac harmonics which gets effectively eliminated with 12 pulse bridge converters are -
A)
triplen harmonics
B)
triplen and 5th harmonics
C)
triplen, 5th and 7th harmonics
D)
5th and 7th harmonics
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'triplen harmonics' (Option A).
Inspector of Factories • Paper-II
For root loci which of the following are starting points?
A)
open loop zeros
B)
closed loop zeros
C)
closed loop poles
D)
open loop poles
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'closed loop zeros' (Option B).
Inspector of Factories • Paper-II
The daily energy produced in a thermal power station is 720 MWh at a load factor of 0.6. What is the maximum demand of the station?
A)
50 MW
B)
30 MW
C)
72 MW
D)
720 MW
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is '720 MW' (Option D).
Inspector of Factories • Paper-II
Ferranti effect on long overhead line is experienced when it is -
A)
lightly loaded
B)
on full load at unity pf
C)
on full load at 0.8 pf
D)
on full load at zero pf
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'on full load at unity pf' (Option B).
Inspector of Factories • Paper-II
The purpose of providing dummy coils in a generator is -
A)
to enhance flux density
B)
to amplify voltage
C)
to provide mechanical balance for the rotor
D)
to reduce eddy currents
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'to enhance flux density' (Option A).
Inspector of Factories • Paper-II
The induced EMF in the armature conductors of a d.c. motor is -
A)
sinusoidal
B)
trapezoidal
C)
rectangular
D)
alternating
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'alternating' (Option D).
Inspector of Factories • Paper-II
Nyquist criterion is used to find which of the following?
A)
absolute stability
B)
relative stability
C)
both (a) & (b)
D)
none of these
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'relative stability' (Option B).
Inspector of Factories • Paper-II
ACSR conductor have the central core made of -
A)
copper
B)
steel
C)
aluminium
D)
cadmium
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'aluminium' (Option C).
Inspector of Factories • Paper-II
In a D.C. generator the critical resistance refers to the resistance of -
A)
brushes
B)
field
C)
armature
D)
load
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'field' (Option B).
Inspector of Factories • Paper-II
The effect of increasing the length of air-gap in an induction motor will be to increase the -
A)
power factor
B)
speed
C)
magnetizing current
D)
air-gap flux
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'magnetizing current' (Option C).
Inspector of Factories • Paper-II
If the fault current is 2 kA, the relay setting is 50% and the C.T ratio is 400/5, then the plug setting multiplier of a relay will be -
A)
5
B)
7
C)
8
D)
10
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is '5' (Option A).
Inspector of Factories • Paper-II
The number of brushes in a commutator depends on -
A)
speed of armature
B)
type of winding
C)
voltage
D)
amount of current to be collected
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'voltage' (Option C).
Inspector of Factories • Paper-II
The field coils of D.C. generators are usually made of -
A)
mica
B)
copper
C)
cast iron
D)
carbon
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'mica' (Option A).
Inspector of Factories • Paper-II
The main purpose of using core in transformer is to -
A)
decrease iron losses
B)
prevent eddy current loss
C)
eliminate magnetic hysteresis
D)
decrease reluctance of the common magnetic circuit
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'prevent eddy current loss' (Option B).
Inspector of Factories • Paper-II
In a power station, the cost of generation of power reduces most effectively when -
A)
diversity factor alone increases
B)
both diversity factor and load factor increase
C)
load factor alone increases
D)
both diversity factor and load factor decrease
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'both diversity factor and load factor decrease' (Option D).
Inspector of Factories • Paper-II
Stepper motor are mostly used for -
A)
high power requirements
B)
control system applications
C)
very high speed of operation
D)
very low speed of operation
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'very low speed of operation' (Option D).
Inspector of Factories • Paper-II
Power transformers are designed to have maximum efficiency at -
A)
nearly full load
B)
70% full load
C)
50% full load
D)
no load
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'no load' (Option D).
