SYNCHRONOUS MOTORS QUIZ

A 50 Hz synchronous motor runs at 200 rpm. The number of salient poles on the rotor are______

36

30

None of the listed here

16

TRUE ANSWER : ?
YOUR ANSWER : ?

A synchronous machine with low value of short-circuit ratio has

lower stability limit

high stability limit

good speed regulation

good voltage regulation

TRUE ANSWER : ?
YOUR ANSWER : ?

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

None of the listed here

minimum

Maximum

Zero

TRUE ANSWER : ?
YOUR ANSWER : ?

The back emf in the stator of a synchronous motor depends on

Rotor excitation

None of the listed here

Rotor speed

Flux density

TRUE ANSWER : ?
YOUR ANSWER : ?

In a synchronous motor, the forced vibrations will be maximum when driving

A centrifugal blower

A centrifugal pump

A reciprocating air compressor

Any of the listed here

TRUE ANSWER : ?
YOUR ANSWER : ?

The direction of rotation of a synchronous motor can be reversed by reversing,

Polarity of rotor poles

Current to field winding

None of the listed here

Supply phase sequence

TRUE ANSWER : ?
YOUR ANSWER : ?

A synchronous capacitor is an over excited motor running at ________

Full load

Half full load

No load

None of the listed here

TRUE ANSWER : ?
YOUR ANSWER : ?

In a synchronous motor, the magnitude of stator back emf depends on _____

Both the speed and rotor flux

Load on the motor

Dc excitation only

Speed of the rotor

TRUE ANSWER : ?
YOUR ANSWER : ?

In a synchronous motor which loss varies with load ?

Core loss

Windage loss

Bearing friction loss

Copper loss

TRUE ANSWER : ?
YOUR ANSWER : ?

In a synchronous motor, the rotor copper loss are met by ______

Armature input

Supply lines

Dc source

Motor input

TRUE ANSWER : ?
YOUR ANSWER : ?

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