The minimum armature current of the synchronous motor corresponds to operation at______________?

A. Zero power factor leading
B. Unity power factor
C. 0.707 power factor lagging
D. 0.707 power factor leading

Synchronous motor always runs at______________?

A. The synchronous speed
B. Less than synchronous speed
C. More than synchronous speed
D. None of the above

Under which of the following conditions hunting of synchronous motor is likely to occur?

A. Periodic variation of load
B. Over-excitation
C. Over-loading for long periods
D. Small and constant load

A synchronous motor is running on a load with normal excitation. Now if the load on the motor is increased

A. Power factor as well as armature current will decrease
B. Power factor as well as armature current will increase
C. Power factor will increase but armature current will decrease
D. Power factor will decrease and armature current will increase

As the load is applied to a synchronous motor, the motor takes more armature current because

A. The increased load has to take more current
B. The rotor by shifting its phase backward causes motor to take more current
C. The back e.m.f. decreases causing an increase in motor current
D. The rotor strengthens the rotating field casuing more motor current

The power developed by a synchronous motor will be maximum when the load angle is____________?

A. Zero
B. 45°
C. 90°
D. 120°

A synchronous motor can be started by________?

A. Pony motor
B. D.c. compound motor
C. Providing damper winding
D. Any of the above

A pony motor is basically a_________?

A. Small induction motor
B. D.c. series motor
C. D.c. shunt motor
D. Double winding a.c./d.c. motor

When the excitation of an unloaded salient pole synchronous motor suddenly gets disconnected______________?

A. The motor stops
B. It runs as a reluctance motor at the same speed
C. It runs as a reluctance motor at a lower speed
D. None of the above

A synchronous motor can be used as a synchronous capacitor when it is____________?

A. Under-loaded
B. Over-loaded
C. Under-excited
D. Over-excited