Inspector of Factories • Paper-II
In a 3-phase, 5 kV, 5 MVA system, what is the base impedance?
A)
5 ohms
B)
50 ohms
C)
500 ohms
D)
0.5 ohms
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is '50 ohms' (Option B).
Inspector of Factories • Paper-II
The speed of a D.C. series motor is -
A)
proportional to the armature current
B)
proportional to the square of the armature current
C)
proportional to field current
D)
inversely proportional to the armature current
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'proportional to the square of the armature current' (Option B).
Inspector of Factories • Paper-II
The skin effect does not depends on -
A)
nature of material
B)
size of wire
C)
supply frequency
D)
temperature
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'size of wire' (Option B).
Inspector of Factories • Paper-II
If the gain of the critical damped system is increased it will behaves as -
A)
oscillatory
B)
critically damped
C)
over damped
D)
under damped
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'under damped' (Option D).
Inspector of Factories • Paper-II
In hydro power stations, what is an enlarged body of water just above the intake and used as a regulating reservoir, called?
A)
Spillways
B)
Forebay
C)
Reservoir
D)
Penstock
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'Spillways' (Option A).
Inspector of Factories • Paper-II
The Y matrix of a 100 bus interconnected system is 90% sparse. Hence the number of transmission bus lines in the system must be -
A)
450
B)
500
C)
900
D)
1000
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is '500' (Option B).
Inspector of Factories • Paper-II
A control system with excessive noise is likely to suffer from -
A)
Saturation in amplifying stage
B)
Loss of gain
C)
Vibration
D)
Oscillation
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'Saturation in amplifying stage' (Option A).
Inspector of Factories • Paper-II
The synchronous reactance is the -
A)
Reactance due to armature reaction of the machine
B)
Reactance due to leakage flux
C)
Combined reactance due to leakage flux and armature reaction
D)
Reactance either due to armature reaction or leakage flux
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'Combined reactance due to leakage flux and armature reaction' (Option C).
Inspector of Factories • Paper-II
A lightning arrestor connected between the line and earth in a power system to -
A)
protects the terminal equipment against travelling surges
B)
protects the transmission line against lightning stroke
C)
suppresses high frequency oscillations in the line
D)
reflects back the travelling wave approaching it
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'protects the terminal equipment against travelling surges' (Option A).
Inspector of Factories • Paper-II
In the circle diagram for induction motor, the diameter of the circle represents -
A)
slip
B)
rotor current
C)
running torque
D)
line voltage
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'running torque' (Option C).
Inspector of Factories • Paper-II
A good control system has all the following features except -
A)
Good stability
B)
Slow response
C)
Good accuracy
D)
Sufficient power handling capacity
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'Slow response' (Option B).
Inspector of Factories • Paper-II
No load test on a transformer is carried out to determine -
A)
copper loss
B)
magnetizing current
C)
magnetizing current and no load loss
D)
efficiency of the transformer
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'efficiency of the transformer' (Option D).
Inspector of Factories • Paper-II
Gain margin is the factor by which the gain of the system is increased to make it -
A)
damped
B)
oscillatory
C)
stable
D)
unstable
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'unstable' (Option D).
Inspector of Factories • Paper-II
How many relays are used to detect inter phase fault of a three line system?
A)
One
B)
Two
C)
Three
D)
Six
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'One' (Option A).
Inspector of Factories • Paper-II
If the speed of a dc motor increases with load torque, then it is a -
A)
series motor
B)
permanent magnet motor
C)
differentially compound motor
D)
cumulatively compound motor
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'permanent magnet motor' (Option B).
Inspector of Factories • Paper-II
The rotor power output of a 3-phase induction motor is 15 kW. The rotor copper losses at a slip of 4% will be -
A)
600 W
B)
625 W
C)
650 W
D)
700 W
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is '700 W' (Option D).
Inspector of Factories • Paper-II
By using guard ring in a transmission line, its string efficiency -
A)
increase
B)
decrease
C)
remain constant
D)
none
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'none' (Option D).
Inspector of Factories • Paper-II
The value of flux involved in the e.m.f. equation of a transformer is -
A)
average value
B)
r.m.s. value
C)
maximum value
D)
instantaneous value
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'instantaneous value' (Option D).
Inspector of Factories • Paper-II
The positive, negative and zero sequence impedances of a solidly grounded system under steady state condition always follow the relation -
A)
Z1 > Z2 > Z0
B)
Z1 < Z2 < Z0
C)
Z0 < Z1 < Z2
D)
Z0 = Z1 = Z2
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'Z0 < Z1 < Z2' (Option C).
Inspector of Factories • Paper-II
An induction motor having 8 poles runs at 727.5 rpm. If the supply frequency is 50 Hz, the emf in the rotor will have a frequency of -
A)
1.5 Hz
B)
48.5 Hz
C)
51.5 Hz
D)
75 Hz
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is '51.5 Hz' (Option C).
Inspector of Factories • Paper-II
A two-winding transformer is used as an auto-transformer. The kVA rating of the auto transformer compared to the two winding transformer will be -
A)
3 times
B)
2 times
C)
1.5 times
D)
same
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is '1.5 times' (Option C).
Inspector of Factories • Paper-II
Which of the following motors one will choose to drive the rotary compressor?
A)
D.C shunt motor
B)
D.C series motor
C)
Universal motor
D)
Synchronous motor
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'D.C series motor' (Option B).
Inspector of Factories • Paper-II
If the pole flux of a d.c. motor approaches zero, its speed will -
A)
approaches zero
B)
approaches infinity
C)
no change due to corresponding change in back emf
D)
approaches a stable value somewhere between zero and infinity
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is 'no change due to corresponding change in back emf' (Option C).
Inspector of Factories • Paper-II
A 6-pole, 50 Hz, 3-phase induction motor has a full load speed of 950 rpm. At half-load, its speed would be -
A)
475 rpm
B)
500 rpm
C)
975 rpm
D)
1000 rpm
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is '500 rpm' (Option B).
Inspector of Factories • Paper-II
If the inertia constant H of a machine of 200 MVA is 2 p.u. its value corresponding to 400 MVA will be -
A)
4.0 p.u.
B)
2.0 p.u.
C)
1.0 p.u.
D)
0.5 p.u
Based on established principles in Electrical / Electronics Engineering, the correct and most appropriate choice is '4.0 p.u.' (Option A).
