Synchronous Motors

The speed of a synchronous motor

If the field of a synchronous motor is under – excited the power factor will be

The minimum armature current of a synchronous motor corresponds to operation at

A 3 phase synchronous motor runs at full load of 1,200 rpm. If the load is reduced to one-half of rated, calculate its speed regulation.

When the excitation of an unloaded salient pole synchronous motor suddenly gets disconnected, then

In a synchronous motor, the rotor copper losses are met by

When the frequency of a synchronous motor increases, what happens to its speed?

The shaft of synchronous motor is made of

In a synchronous machine, when the rotor speed becomes more than the synchronous speed during hunting, the damping bars develop ______ torque.

Synchronous motors are

If the torque angle continuously increases, system will become

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

What is the reason why a synchronous motor is not self starting?

The construction of synchronous motor is similar to which of the following machines?

Which of the following will change the speed of a synchronous motor?

How do you call the maximum sustained torque which a synchronous motor will develop at synchronous speed with rated frequency and rated field current?

How do you call the maximum value of torque that a synchronous motor can develop without lossing its synchronism?

A synchronous motor is rotating in a certain direction. What will happen if the direction of its field current is reversed?

What is the purpose of damper windings provided in synchronous machines?

The size of a synchronous motor is determined from which of the following?