Practice Single Phase Induction Motors Multiple Choice Questions Quiz-1

Q.1

In a A.C. series motor armature coils are usually connected to commutator

through resistance
through reactances
through capacitors
solidly

Q.2

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.3

The speed of a universal motor is usually reduced by using

gearing
belts
brakes
chains

Q.4

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.5

The shaded pole motor is used for

high starting torque
low starting torque
medium starting torque
very high starting torque

Q.6

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.7

The power factor of a single-phase induction motor is usually

lagging
always leading
unity
unity to 0.8 leading

Q.8

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.9

Which of the following motors is inherently self starting ?

Split motor
Shaded-pole motor
Reluctance motor
None of these

Q.10

In which single-phase motor, the rotor has no teeth or winding ?

Split phase motor
Reluctance motor
Hysteresis motor
Universal motor

Q.11

For which of the applications a reluctance motor is preferred ?

Electric shavers
Refrigerators
Signalling and timing devices
Lifts and hoists

Q.12

The electric motor used in portable drills is

capacitor run motor
hysteresis motor
universal motor
repulsion motor

Q.13

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.14

The rotor developed by a single-phase motor at starting is

more than rated torque
rated torque
less than the rated torque
zero

Q.15

Torque developed by a single phase induction motor at starting is

pulsating
uniform
none of the above
nil

Q.16

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.17

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.18

The motor used on small lathes is usually

universal motor
D.C. shunt motor
single-phase capacitor run motor
3-phase synchronous motor

Q.19

The speed of a universal motor is generally reduced by using

gear trains
V-belts
brakes
chains

Q.20

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.21

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.22

A universal motor is one which

can be operated either on D.C. or A.C. 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.23

Which of the following motor will have relatively higher power factor ?

Capacitor run motor
Shaded pole motor
Capacitor start motor
Split phase motor

Q.24

As hysteresis motors are free from mechanical and magnetic vibrations therefore these are considered as suitable for

fans
blowers
sound equipment
mixer grinders

Q.25

The speed control of universal motor used for sewing machines is by

friction
varying the resistance
tapping the field
centrifugal mechanism

Q.26

In a shaded pole single-phase motor, the revolving field is produced by the use of

inductor
capacitor
resistor
shading coils

Q.27

The starting winding of a single-phase motor is placed in

Armature
Field
Rotor
Stator

Q.28

In case of high speed universal motor which of the following needs more attention ?

End play
Air gap
Insulation in rotor
Balancing of rotor

Q.29

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.30

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

In a A.C. series motor armature coils are usually connected to commutator

Which of the following statements regarding reluctance-start motor is incorrect ?

The speed of a universal motor is usually reduced by using

In a shaded pole motor, the shading coil usually consist of

The shaded pole motor is used for

After the starting winding of a single phase induction motor is disconnected from supply, it continues to run only on

The power factor of a single-phase induction motor is usually

Direction of rotation of a split phase motor can be reversed by reversing the connection of

Which of the following motors is inherently self starting ?

In which single-phase motor, the rotor has no teeth or winding ?

For which of the applications a reluctance motor is preferred ?

The electric motor used in portable drills is

In A.C. series motor compensating winding is employed to

The rotor developed by a single-phase motor at starting is

Torque developed by a single phase induction motor at starting is

Speed control of a universal motor is achieved by

When a D.C. series motor is connected to A.C. supply, the power factor will be low because of

The motor used on small lathes is usually

The speed of a universal motor is generally reduced by using

Starting winding of a single phase motor of a refrigerator is disconnected from the circuit by means of a

To reverse the direction of rotation of acapacitor start motor while it is running we should

A universal motor is one which

Which of the following motor will have relatively higher power factor ?

As hysteresis motors are free from mechanical and magnetic vibrations therefore these are considered as suitable for

The speed control of universal motor used for sewing machines is by

In a shaded pole single-phase motor, the revolving field is produced by the use of

The starting winding of a single-phase motor is placed in

In case of high speed universal motor which of the following needs more attention ?

A centrifugal switch is used to disconnect starting winding when motor has

Which of the following statements regarding two value capacitor motor is incorrect ?

0 h : 0 m : 1 s

Support mcqgeeks.com by disabling your adblocker.