Most Important Synchronous Motor MCQs

Synchronous motors are the electrical machines that convert AC electrical power to mechanical power. Electrical Engineering XYZ shares 10 Most Important synchronous motors MCQs.

Contents

Sort The advantages of amortisseur winding

Sort The advantages of amortisseur winding:

1. It increases stability
2. It develops torque which is useful for fast machine
3. It develops torque which is useful for slow machines
4. All of these

Correct answer: 4. All of these

The correct statement about the speed of synchronous motor

The correct statement about the speed of synchronous motor:

4. It is pulsating and change at irregular intervals

The synchronous motor is not a self starting motor because

The synchronous motor is not a self starting motor because:

1. It uses damper winding
2. No stator is present
3. The slip is zero in the motor
4. The rotor’s instantaneous torque reverses after half cycle

Correct answer: 4. The rotor’s instantaneous torque reverses after half cycle

The overexcited synchronous motor is used to

The overexcited synchronous motor is used to:

2. Support loads which have low torque
3. Supply reactive power
4. None of these

Correct answer: 3. Supply reactive power

Explanation: The overexcited synchronous motor provides reactive power to the power system and it can be used for the power factor correction

The method which can be used to start a synchronous motor

The method which can be used to start a synchronous motor:

1. Use an external prime mover
2. Reduce the stator frequency to safe point
3. Use Amortisseur windings
4. All of these

Correct answer: 4. All of these

Speed regulation of the Synchronous motor is

Speed regulation of synchronous motor is:

1. 0
2. 1
3. 10
4. 100

The maximum pullout torque in a synchronous motor occurs at

The maximum pullout torque in a synchronous motor occurs at:

1. 45º
2. 60º
3. 90º

Synchronous motors are self-starting, the statement is

Synchronous motors are self-starting, the statement is:

1. True
2. False

The power factor of under excited synchronous motor is

The power factor of under excited synchronous motor is:

2. Lagging
3. Unity
4. Zero

The percent slip of synchronous motor is

The percent slip of synchronous motor is:

1. 0
2. 0.5
3. 99.5
4. 100