The power demand can be estimated approximately by____________?

A. Load survey method
B. Mathematical method
C. Statistical method
D. Economic parameters

Power electronics essentially deals with control of a.c. power at____________?

A. Frequencies above 20 khz
B. Frequencies above 1000 khz
C. Frequencies less than 10 hz
D. 50 hz frequency

A synchronous motor can develop synchronous torque:

A. When under loaded
B. While over-excited
C. Only at synchronous speed
D. Below or above synchronous speed

The maximum power developed in a synchronous motor will depend on__________?

A. The rotor excitation only
B. The supply voltage only
C. The rotor excitation and supply volt-age both
D. The rotor excitation, supply voltage and maximum value of coupling angle (90°)

In a synchronous motor, the breakdown torque is__________?

A. Directly proportional to the square of the applied voltage
B. Directly proportional to applied voltage
C. Inversely proportional to applied voltage
D. None of the above

A synchronous motor which works on a leading power factor and does not drive a mechanical load is called as_________?

A. Static condenser
B. Condenser
C. Synchronous condenser
D. None of the above

If the synchronous motor, properly synchronised to the supply is running on no load and is having negligible loss then_____________?

A. The stator current will be zero
B. The stator current will be very small
C. The stator current will be very high
D. The back e.m.f. will be more than the supply voltage

The coupling angle or load angle of synchronous motor is defined as the angle between the__________?

A. Rotor and stator teeth
B. Rotor and the stator poles of opposite polarity
C. Rotor and the stator poles of the same polarity
D. None of the above

The maximum torque which a synchronous motor will develop at rest for any angular position of the rotor, at rated stator supply voltage and frequency, is known as__________?

A. Locked-rotor torque
B. Synchronous torque
C. Pull up torque
D. Reluctance torque

If the field winding of an unloaded salient pole synchronous motor is open circuited, the motor will__________?

A. Stop
B. Run as induction motor
C. Function as static condenser
D. Burn with dense smoke