SYNCHRONOUS MOTORS QUIZ

When the synchronous motor runs at synchronous speed, the voltage induced in the damper winding is _____

minimum

None of the listed here

Maximum

Zero

TRUE ANSWER : ?
YOUR ANSWER : ?

When the field of a synchronous motor is under-excited, the power factor will be

lagging

zero

unity

leading

TRUE ANSWER : ?
YOUR ANSWER : ?

In order to to reverse the direction of a synchronous motor, _______

Change supply frequency

Interchange any two stator lines

Reduce dc field excitation to zero

None of the listed here

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YOUR ANSWER : ?

The size of a synchronous motor decreases with the increase in

All of the listed here

Flux density

Speed

Horse power rating

TRUE ANSWER : ?
YOUR ANSWER : ?

A synchronous motor delivers reactive power when ______

None of the listed here

Normally excited

Under excited

Over excited

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YOUR ANSWER : ?

The magnitude of field flux in a 3-phase synchronous motor

Varies with speed

Remains constant at all loads

Varies with the load

Varies with power factor

TRUE ANSWER : ?
YOUR ANSWER : ?

Synchronous motor always run at

More than synchronous speed

The synchronous speed

None of the listed here

Less than synchronous speed

TRUE ANSWER : ?
YOUR ANSWER : ?

A synchronous motor can operate at

Leading power factor

Unity power factor only

Lagging power factor only

Lagging, leading and unity power factors

TRUE ANSWER : ?
YOUR ANSWER : ?

When load on a synchronous motor is increased, its armature current is increased provided, it is ______

Normally excited

Under-excited

Over-excited

All of these

TRUE ANSWER : ?
YOUR ANSWER : ?

The mechanical power developed by a synchronous motor is independent of _________.

Speed

Applied stator voltage

Field excitation

Torque angle

TRUE ANSWER : ?
YOUR ANSWER : ?

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