A capacitor-start single phase induction motor is switched on to supply with itscapacitor replaced by an inductor of equivalent reactance value. It will
start and then stop
start and run slowly
start and run at rated speed
not start at all
Q.2.
Burning out of windings is due to
short circuited capacitor
capacitor value hiving changed
open circuiting of capacitor
none of the above
Q.3.
The electric motor used in portable drills is
capacitor run motor
hysteresis motor
universal motor
repulsion motor
Q.4.
For which of the applications a reluctance motor is preferred ?
Electric shavers
Refrigerators
Signalling and timing devices
Lifts and hoists
Q.5.
In A.C. series motor compensating winding is employed to
reduce the effects of armature reaction
increase the torque
reduce sparking at the brushes
none of the above
Q.6.
A centrifugal switch is used to disconnect starting winding when motor has
run for about 1 minute
run for about 5 minutes
picked up about 50 to 70 per cent of rated speed
picked up about 10 to 25 per cent of rated speed
Q.7.
In a A.C. series motor armature coils are usually connected to commutator
through resistance
through reactances
through capacitors
solidly
Q.8.
Which of the following motors is inherently self starting ?
Split motor
Shaded-pole motor
Reluctance motor
None of these
Q.9.
In which single-phase motor, the rotor has no teeth or winding ?
Split phase motor
Reluctance motor
Hysteresis motor
Universal motor
Q.10.
In a shaded pole single-phase motor, the revolving field is produced by the use of
inductor
capacitor
resistor
shading coils
Q.11.
Direction of rotation of a split phase motor can be reversed by reversing the connection of
running winding only
starting winding only
either (A) or (B)
both (A) and (B)
Q.12.
Which of the following statements regarding reluctance-start motor is incorrect ?
It is similar to reluctance motor
It is basically an induction motor and not a synchronous one
So far as its basic working principle is concerned, it is similar to shaded pole motor
the air-gap between rotor and salient poles is non- uniform
Q.13.
Which of the following statements regarding two value capacitor motor is incorrect ?
It is a reversing motor
It is preferred to permanent-split single-value capacitor motor where frequent reversals are required
It has low starting as well as rushing currents
It has high starting torque
Q.14.
Speed control of a universal motor is achieved by
Varying field flux with tapped field windings
Connecting rheostat in series
Applying variable voltage by means of silicon controlled rectifier
All of the above methods
Q.15.
Torque developed by a single phase induction motor at starting is
pulsating
uniform
none of the above
nil
Q.16.
The rotor developed by a single-phase motor at starting is
more than rated torque
rated torque
less than the rated torque
zero
Q.17.
The speed of a universal motor is usually reduced by using
gearing
belts
brakes
chains
Q.18.
The motor used on small lathes is usually
universal motor
shunt motor
single-phase capacitor run motor
3-phase synchronous motor
Q.19.
After the starting winding of a single phase induction motor is disconnected from supply, it continues to run only on
running winding
rotor winding
field winding
compensating winding
Q.20.
The power factor of a single-phase induction motor is usually
lagging
always leading
unity
unity to 0.8 leading
Q.21.
Starting winding of a single phase motor of a refrigerator is disconnected from the circuit by means of a
Magnetic relay
Thermal relay
Centrifugal switch
None of the above
Q.22.
To reverse the direction of rotation of acapacitor start motor while it is running we should
disconnect motor from the supply till it stops then reconnect it to supply with reversed connection of main or auxiliary winding
disconnect motor from supply and immediately reconnect it to supply with reversed con-nections of the main winding
reverse the direction of connection of the auxiliary winding and after motor comes to rest then connect auxiliary winding to the supply
reverse the direction of connections of the auxiliary winding and immediately connect it to supply
Q.23.
A universal motor is one which
can be operated either on or supply at approximately the same speed and output
can be marketed internationally
runs at dangerously high speed on no-load
none of the above
Q.24.
In a shaded pole motor, the shading coil usually consist of
a single turn of heavy wire which is in parallel with running winding
a single turn of heavy copper wire which is short-circuited and carries only induced current
a multilayer fine gauge copper wire in parallel with running winding
none of the above
Q.25.
The shaded pole motor is used for
high starting torque
low starting torque
medium starting torque
very high starting torque
Q.26.
When a D.C. series motor is connected to A.C. supply, the power factor will be low because of
high inductance of field and armature circuits
induced current in rotor due to variations of flux
fine copper wire winding
none of the above
Q.27.
The speed of a universal motor is generally reduced by using
gear trains
V-belts
brakes
chains
Q.28.
In split-phase motor auxiliary winding is of
thick wire placed at the bottom of the slots
thick wire placed at the top of the slots
thin wire placed at the top of the slots
thin wire placed at the bottom of the slots
Q.29.
In a capacitor start motor, the phase displacement between starting and running winding can be nearly
10°
30°
60°
90°
Q.30.
Which of the following single-phase induction motors is generally used in time phonographs?
Resistance start
Capacitor start capacitor run
Shaded pole
Universal
Support mcqgeeks.com by disabling your adblocker.
Please disable the adBlock and continue. Thank you.