Which of the following single-phase motors has relatively poor starting torque ?

All single phase motors have zero starting torque

Which of the following statements regarding hysteresis motor is in incorrect ?

Its high starting torque is due to its high rotor hysteresis loss

It is extremely sensitive to fluctuations in supply voltage

Its high starting torque is due to its high rotor hysteresis loss

It is extremely quiet in operation

It accelerates from rest to full-speed almost instantaneously

In repulsion motor direction of rotation of motor

is opposite to that of brush shift

is the same as that of brush shift

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

picked up about 10 to 25 per cent of rated speed

picked up about 50 to 70 per cent of rated speed

picked up about 10 to 25 per cent of rated speed

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

reduce the effects of armature reaction

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

It has low starting as well as rushing currents

It is preferred to permanent-split single-value capacitor motor where frequent reversals are required

It has low starting as well as rushing currents

Speed control of a universal motor is achieved by

Varying field flux with tapped field windings

Applying variable voltage by means of silicon controlled rectifier

The motor used on small lathes is usually

single-phase capacitor run motor

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

induced current in rotor due to variations of flux

high inductance of field and armature circuits

induced current in rotor due to variations of flux

A universal motor is one which

can be marketed internationally

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

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

disconnect motor from supply and immediately reconnect it to supply with reversed con-nections of the main winding

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

The direction of rotation of universal motor can be reversed the by reversing the flow of current through%!

Either armature winding or field winding

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

picked up about 10 to 25 per cent of rated speed

picked up about 50 to 70 per cent of rated speed

picked up about 10 to 25 per cent of rated speed

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

It has low starting as well as rushing currents

It is preferred to permanent-split single-value capacitor motor where frequent reversals are required

It has low starting as well as rushing currents

A universal motor is one which%!

can be marketed internationally

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

*/*_If the centrifugal switch of a two-value capacitor motor using two capacitors fails to open then?

motor will not come up to speed

current drawn by the motor will be excessively high

electrolytic capacitor will, in all probability, suffer break down

*/*_In case of a shaded pole motor the direction of rotation of the motor is?

either of the above depending on voltage

either of the above depending on power factor

*/*_Which of the following motor will give the highest starting torque ??

Repulsion start and induction run motor

*/*_In repulsion motor, zero torque is developed when?

brush axis is 45¬¨‚àû electrical to field axis

brush axis coincides with the field axis

brush axis is 90¬¨‚àû electrical to field axis

*/*_A centrifugal switch is used to disconnect starting winding when motor has?

picked up about 10 to 25 per cent of rated speed

picked up about 50 to 70 per cent of rated speed

picked up about 10 to 25 per cent of rated speed

*/*_Which of the following statements regarding two value capacitor motor is incorrect ??

It has low starting as well as rushing currents

It is preferred to permanent-split single-value capacitor motor where frequent reversals are required

It has low starting as well as rushing currents

*/*_A universal motor is one which?

can be marketed internationally

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

*/*_The purpose of stator winding in the compensated repulsion motor is to?

improve power factor and provide better speed regulation

*/*_A single-phase induction motor is?

inherently non-self-starting with high torque

inherently self-starting with high torque

inherently self-starting with low torque

inherently non-self-starting with low torque

inherently non-self-starting with high torque

240 + Mcqs in Single Phase Induction Motors in Electrical Engineering Page 3 McqOptions

101.	If a single phase induction motor runs slower than normal, the most likely defect is
A.	worn bearings
B.	short-circuit in the winding
C.	open-circuit in the winding
D.	none of the above
Answer» B. short-circuit in the winding

Discussion

102.	Which of the following single-phase motors has relatively poor starting torque ?
A.	Universal motor
B.	Repulsion motor
C.	Capacitor motor
D.	All single phase motors have zero starting torque
Answer» D. All single phase motors have zero starting torque

Discussion

103.	Which of the following statements regarding hysteresis motor is in incorrect ?
A.	It is extremely sensitive to fluctuations in supply voltage
B.	Its high starting torque is due to its high rotor hysteresis loss
C.	It is extremely quiet in operation
D.	It accelerates from rest to full-speed almost instantaneously
Answer» B. Its high starting torque is due to its high rotor hysteresis loss

Discussion

104.	Centrifugal switch disconnects the auxiliary winding of the motor at about ____ percent of synchronous speed
A.	30 to 40
B.	70 to 80
C.	80 to 90
D.	100
Answer» C. 80 to 90

Discussion

105.	In repulsion motor direction of rotation of motor
A.	is opposite to that of brush shift
B.	is the same as that of brush shift
C.	is independent of brush shift
D.
Answer» C. is independent of brush shift

Discussion

106.	In a universal motor, the most common cause of brush sparking is
A.	open armature winding
B.	shorted armature winding
C.	shorted field winding?
D.	high commutator mica
E.	all of the above
Answer» F.

Discussion

107.	In a shaded pole single-phase motor, the revolving field is produced by the use of
A.	inductor
B.	capacitor
C.	resistor
D.	shading coils
Answer» E.

Discussion

108.	In which single-phase motor, the rotor has no teeth or winding ?
A.	Split phase motor
B.	Reluctance motor
C.	Hysteresis motor
D.	Universal motor
Answer» D. Universal motor

Discussion

109.	Which of the following motors is inherently self starting ?
A.	Split motor
B.	Shaded-pole motor
C.	Reluctance motor
D.	None of these
Answer» C. Reluctance motor

Discussion

110.	A centrifugal switch is used to disconnect starting winding when motor has
A.	run for about 1 minute
B.	run for about 5 minutes
C.	picked up about 50 to 70 per cent of rated speed
D.	picked up about 10 to 25 per cent of rated speed
Answer» D. picked up about 10 to 25 per cent of rated speed

Discussion

111.	In A.C. series motor compensating winding is employed to
A.	reduce the effects of armature reaction
B.	increase the torque
C.	reduce sparking at the brushes
D.	none of the above
Answer» D. none of the above

Discussion

112.	The electric motor used in portable drills is
A.	capacitor run motor
B.	hysteresis motor
C.	universal motor
D.	repulsion motor
Answer» D. repulsion motor

Discussion

113.	Which of the following statements regarding two value capacitor motor is incorrect ?
A.	It is a reversing motor
B.	It is preferred to permanent-split single-value capacitor motor where frequent reversals are required
C.	It has low starting as well as rushing currents
D.	It has high starting torque
Answer» C. It has low starting as well as rushing currents

Discussion

114.	Speed control of a universal motor is achieved by
A.	Varying field flux with tapped field windings
B.	Connecting rheostat in series
C.	Applying variable voltage by means of silicon controlled rectifier
D.	All of the above methods
Answer» E.

Discussion

115.	Torque developed by a single phase induction motor at starting is
A.	pulsating
B.	uniform
C.	none of the above
D.	nil
Answer» E.

Discussion

116.	The speed of a universal motor is generally reduced by using
A.	gear trains
B.	V-belts
C.	brakes
D.	chains
Answer» B. V-belts

Discussion

117.	The motor used on small lathes is usually
A.	universal motor
B.	D.C. shunt motor
C.	single-phase capacitor run motor
D.	3-phase synchronous motor
Answer» D. 3-phase synchronous motor

Discussion

118.	When a D.C. series motor is connected to A.C. supply, the power factor will be low because of
A.	high inductance of field and armature circuits
B.	induced current in rotor due to variations of flux
C.	fine copper wire winding
D.	none of the above
Answer» B. induced current in rotor due to variations of flux

Discussion

119.	A universal motor is one which
A.	can be operated either on D.C. or A.C. supply at approximately the same speed and output
B.	can be marketed internationally
C.	runs at dangerously high speed on no-load
D.	none of the above
Answer» B. can be marketed internationally

Discussion

120.	To reverse the direction of rotation of acapacitor start motor while it is running we should
A.	disconnect motor from the supply till it stops then reconnect it to supply with reversed connection of main or auxiliary winding
B.	disconnect motor from supply and immediately reconnect it to supply with reversed con-nections of the main winding
C.	reverse the direction of connection of the auxiliary winding and after motor comes to rest then connect auxiliary winding to the supply
D.	reverse the direction of connections of the auxiliary winding and immediately connect it to supply
Answer» B. disconnect motor from supply and immediately reconnect it to supply with reversed con-nections of the main winding

Discussion

121.	Starting winding of a single phase motor of a refrigerator is disconnected from the circuit by means of a
A.	Magnetic relay
B.	Thermal relay
C.	Centrifugal switch
D.	None of the above
Answer» B. Thermal relay

Discussion

122.	Which of the following motors is used in mixies ?
A.	Repulsion motor
B.	Reluctance motor
C.	Hysteresis motor
D.	Universal motor
Answer» E.

Discussion

123.	Which of the following motors is preferred for tape-recorders?
A.	Shaded pole motor
B.	Hysteresis motor
C.	Two value capacitor motor
D.	Universal motor
Answer» C. Two value capacitor motor

Discussion

124.	Which type of load is offered by cranes and hoists ?
A.	Gradually varying load
B.	Non-reversing, no-load start
C.	Reversing, light start
D.	Reversing, heavy start
Answer» E.

Discussion

125.	The wattage rating for a ceiling fan motor will be in the range%!
A.	200 to 250 W
B.	250 to 500 W
C.	50 to 150 W
D.	10 to 20 W
Answer» D. 10 to 20 W

Discussion

126.	The direction of rotation of universal motor can be reversed the by reversing the flow of current through%!
A.	Armature winding
B.	Field winding
C.	Either armature winding or field winding
D.	None of the above
Answer» D. None of the above

Discussion

127.	Which of the following motors is used for unity power factor ?%!
A.	Hysteresis motor
B.	Schrage motor
C.	Universal motor
D.	Reluctance motor
Answer» C. Universal motor

Discussion

128.	Which of the following motors can be used for unity power factor ?%!
A.	Capacitor run motor
B.	Shaded pole motor
C.	Hysteresis motor
D.	Schrage motor
Answer» E.

Discussion

129.	A centrifugal switch is used to disconnect starting winding when motor has%!
A.	run for about 1 minute
B.	run for about 5 minutes
C.	picked up about 50 to 70 per cent of rated speed
D.	picked up about 10 to 25 per cent of rated speed
Answer» D. picked up about 10 to 25 per cent of rated speed

Discussion

130.	In a shaded pole single-phase motor, the revolving field is produced by the use of%!
A.	inductor
B.	capacitor
C.	resistor
D.	shading coils
Answer» E.

Discussion

131.	The speed of a universal motor is generally reduced by using%!
A.	gear trains
B.	V-belts
C.	brakes
D.	chains
Answer» B. V-belts

Discussion

132.	Which of the following statements regarding two value capacitor motor is incorrect ?%!
A.	It is a reversing motor
B.	It is preferred to permanent-split single-value capacitor motor where frequent reversals are required
C.	It has low starting as well as rushing currents
D.	It has high starting torque
Answer» C. It has low starting as well as rushing currents

Discussion

133.	A universal motor is one which%!
A.	can be operated either on D.C. or A.C. supply at approximately the same speed and output
B.	can be marketed internationally
C.	runs at dangerously high speed on no-load
D.	none of the above
Answer» B. can be marketed internationally

Discussion

134.	/_If a single phase induction motor runs slower than normal, the most likely defect is?
A.	worn bearings
B.	short-circuit in the winding
C.	open-circuit in the winding
D.	none of the above
Answer» B. short-circuit in the winding

Discussion

135.	/_If the centrifugal switch of a two-value capacitor motor using two capacitors fails to open then?
A.	motor will not come up to speed
B.	motor will not carry the load
C.	current drawn by the motor will be excessively high
D.	electrolytic capacitor will, in all probability, suffer break down
Answer» E.

Discussion

136.	/_The repulsion start induction run motor is used because of?
A.	good power factor
B.	high efficiency
C.	minimum cost
D.	high starting torque
Answer» E.

Discussion

137.	/_In case of a shaded pole motor the direction of rotation of the motor is?
A.	from main pole to shaded pole
B.	from shaded pole to main pole
C.	either of the above depending on voltage
D.	either of the above depending on power factor
Answer» B. from shaded pole to main pole

Discussion

138.	/_Which of the following motor will give the highest starting torque ??
A.	D.C. shunt motor
B.	Schrage motor
C.	Repulsion start and induction run motor
D.	Universal motor
Answer» C. Repulsion start and induction run motor

Discussion

139.	/_In repulsion motor, zero torque is developed when?
A.	brush axis is 45¬¨‚àû electrical to field axis
B.	brush axis coincides with the field axis
C.	brush axis is 90¬¨‚àû electrical to field axis
D.	both (B) and (C)
Answer» E.

Discussion

140.	/_In a shaded pole single-phase motor, the revolving field is produced by the use of?
A.	inductor
B.	capacitor
C.	resistor
D.	shading coils
Answer» E.

Discussion

141.	/_A centrifugal switch is used to disconnect starting winding when motor has?
A.	run for about 1 minute
B.	run for about 5 minutes
C.	picked up about 50 to 70 per cent of rated speed
D.	picked up about 10 to 25 per cent of rated speed
Answer» D. picked up about 10 to 25 per cent of rated speed

Discussion

142.	/_Which of the following statements regarding two value capacitor motor is incorrect ??
A.	It is a reversing motor
B.	It is preferred to permanent-split single-value capacitor motor where frequent reversals are required
C.	It has low starting as well as rushing currents
D.	It has high starting torque
Answer» C. It has low starting as well as rushing currents

Discussion

143.	/_The speed of a universal motor is generally reduced by using?
A.	gear trains
B.	V-belts
C.	brakes
D.	chains
Answer» B. V-belts

Discussion

144.	/_A universal motor is one which?
A.	can be operated either on D.C. or A.C. supply at approximately the same speed and output
B.	can be marketed internationally
C.	runs at dangerously high speed on no-load
D.	none of the above
Answer» B. can be marketed internationally

Discussion

145.	/_In a capacitor start motor, the phase displacement between starting and running winding can be nearly?
A.	10¬¨‚àû
B.	30¬¨‚àû
C.	60¬¨‚àû
D.	90¬¨‚àû
Answer» E.

Discussion

146.	/_The range of efficiency for shaded pole motors is?
A.	95% to 99%
B.	80% to 90%
C.	50% to 75%
D.	5% to 35%
Answer» E.

Discussion

147.	/_The purpose of stator winding in the compensated repulsion motor is to?
A.	provide mechanical balance
B.	improve power factor and provide better speed regulation
C.	prevent hunting in the motor
D.	eliminate armature reaction
Answer» C. prevent hunting in the motor

Discussion

148.	/_A single-phase induction motor is?
A.	inherently self-starting with high torque
B.	inherently self-starting with low torque
C.	inherently non-self-starting with low torque
D.	inherently non-self-starting with high torque
Answer» D. inherently non-self-starting with high torque

Discussion

149.	/_Which of the following motors is used in tape-recorders ??
A.	Hysteresis motor
B.	Reluctance motor
C.	Capacitor-run motor
D.	Universal motor
Answer» B. Reluctance motor

Discussion

150.	/_Speed torque characteristic of a repulsion induction motor is similar to that of a D.C.?
A.	shunt motor
B.	series motor
C.	compound motor
D.	separately excited motor
Answer» D. separately excited motor

Discussion

Explore topic-wise MCQs in Electrical Engineering.

If a single phase induction motor runs slower than normal, the most likely defect is

Which of the following single-phase motors has relatively poor starting torque ?

Which of the following statements regarding hysteresis motor is in incorrect ?

Centrifugal switch disconnects the auxiliary winding of the motor at about ____ percent of synchronous speed

In repulsion motor direction of rotation of motor

In a universal motor, the most common cause of brush sparking is

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

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

Which of the following motors is inherently self starting ?

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

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

The electric motor used in portable drills is

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

Speed control of a universal motor is achieved by

Torque developed by a single phase induction motor at starting is

The speed of a universal motor is generally reduced by using

The motor used on small lathes is usually

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

A universal motor is one which

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

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

Which of the following motors is used in mixies ?

Which of the following motors is preferred for tape-recorders?

Which type of load is offered by cranes and hoists ?

The wattage rating for a ceiling fan motor will be in the range%!

The direction of rotation of universal motor can be reversed the by reversing the flow of current through%!

Which of the following motors is used for unity power factor ?%!

Which of the following motors can be used for unity power factor ?%!

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

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

The speed of a universal motor is generally reduced by using%!

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

A universal motor is one which%!

*/*_If a single phase induction motor runs slower than normal, the most likely defect is?

*/*_If the centrifugal switch of a two-value capacitor motor using two capacitors fails to open then?

*/*_The repulsion start induction run motor is used because of?

*/*_In case of a shaded pole motor the direction of rotation of the motor is?

*/*_Which of the following motor will give the highest starting torque ??

*/*_In repulsion motor, zero torque is developed when?

*/*_In a shaded pole single-phase motor, the revolving field is produced by the use of?

*/*_A centrifugal switch is used to disconnect starting winding when motor has?

*/*_Which of the following statements regarding two value capacitor motor is incorrect ??

*/*_The speed of a universal motor is generally reduced by using?

*/*_A universal motor is one which?

*/*_In a capacitor start motor, the phase displacement between starting and running winding can be nearly?

*/*_The range of efficiency for shaded pole motors is?

*/*_The purpose of stator winding in the compensated repulsion motor is to?

*/*_A single-phase induction motor is?

*/*_Which of the following motors is used in tape-recorders ??

*/*_Speed torque characteristic of a repulsion induction motor is similar to that of a D.C.?

/_If a single phase induction motor runs slower than normal, the most likely defect is?

/_If the centrifugal switch of a two-value capacitor motor using two capacitors fails to open then?

/_The repulsion start induction run motor is used because of?

/_In case of a shaded pole motor the direction of rotation of the motor is?

/_Which of the following motor will give the highest starting torque ??

/_In repulsion motor, zero torque is developed when?

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

/_A centrifugal switch is used to disconnect starting winding when motor has?

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

/_The speed of a universal motor is generally reduced by using?

/_A universal motor is one which?

/_In a capacitor start motor, the phase displacement between starting and running winding can be nearly?

/_The range of efficiency for shaded pole motors is?

/_The purpose of stator winding in the compensated repulsion motor is to?

/_A single-phase induction motor is?

/_Which of the following motors is used in tape-recorders ??

/_Speed torque characteristic of a repulsion induction motor is similar to that of a D.C.?