Study mode · no timer

Single Phase Induction Motors

Study 110 Electrical Engineering MCQs with correct answers and explanations.

Answers and explanations are always visible Take this test

21Electrical EngineeringMedium

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

AHysteresis motor

BSchrage motor

CReluctance motor

DUniversal motor

Correct answer

B. Schrage motor

Explanation

The correct answer is Schrage motor.

22Electrical EngineeringMedium

If the centrifugal switch does not open at 70 to 80 percent of synchronous speed of motor, it would result in________?

Aoverloading of running winding

Bnone of the above

Cdamage to the centrifugal switch

Ddamage to the starting winding

Correct answer

D. damage to the starting winding

Explanation

The correct answer is damage to the starting winding.

23Electrical EngineeringMedium

Which of the following motors is inherently self starting?

ANone of these

BSplit motor

CShaded-pole motor

DReluctance motor

Correct answer

C. Shaded-pole motor

Explanation

The correct answer is Shaded-pole motor.

24Electrical EngineeringMedium

In split phase motor main winding is of ________?

Athin wire placed at the bottom of the slots

Bthick wire placed at the bottom of the slots

Cthick wire placed at the top of the” slots

Dthin wire placed at the top of the slots

Correct answer

B. thick wire placed at the bottom of the slots

Explanation

The correct answer is thick wire placed at the bottom of the slots.

25Electrical EngineeringMedium

In capacitor start single-phase motors________?

Anone of the above

Bcurrent in the starting winding leads the voltage

Ccurrent in the starting winding lags the voltage

Dcurrent in the starting winding is in phase with voltage in running winding

Correct answer

B. current in the starting winding leads the voltage

Explanation

The correct answer is current in the starting winding leads the voltage.

26Electrical EngineeringMedium

In a capacitor start motor, the phase displacement between starting and running winding can be nearly________?

A30°

B90°

C60°

D10°

Correct answer

B. 90°

Explanation

The correct answer is 90°.

27Electrical EngineeringMedium

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

A100

B70 to 80

C30 to 40

D80 to 90

Correct answer

B. 70 to 80

Explanation

The correct answer is 70 to 80.

28Electrical EngineeringMedium

In case of a shaded pole motor the direction of rotation of the motor is________?

Aeither of the above depending on voltage

Bfrom shaded pole to main pole

Ceither of the above depending on power factor

Dfrom main pole to shaded pole

Correct answer

D. from main pole to shaded pole

Explanation

The correct answer is from main pole to shaded pole.

29Electrical EngineeringMedium

Which of the following motors will operate at high power factor?

ASplit phase motor

BCapacitor run motor

CShaped pole motor

DCapacitor start motor

Correct answer

B. Capacitor run motor

Explanation

The correct answer is Capacitor run motor.

30Electrical EngineeringMedium

The motor used on small lathes is usually________?

A3-phase synchronous motor

Buniversal motor

CD.C. shunt motor

Dsingle-phase capacitor run motor

Correct answer

D. single-phase capacitor run motor

Explanation

The correct answer is single-phase capacitor run motor.

In split phase motor main winding is of ________?

Athin wire placed at the bottom of the slots

Bthick wire placed at the bottom of the slots

Cthick wire placed at the top of the” slots

Dthin wire placed at the top of the slots

Correct answer

B. thick wire placed at the bottom of the slots

Explanation

The correct answer is thick wire placed at the bottom of the slots.

In capacitor start single-phase motors________?

Anone of the above

Bcurrent in the starting winding leads the voltage

Ccurrent in the starting winding lags the voltage

Dcurrent in the starting winding is in phase with voltage in running winding

Correct answer

B. current in the starting winding leads the voltage

Explanation

The correct answer is current in the starting winding leads the voltage.