A synchronous machine with low value of short-circuit ratio has___________?

A. Lower stability limit
B. High stability limit
C. Good speed regulation
D. Good voltage regulation

The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as___________?

A. Pull-up torque
B. Pull-in torque
C. Pull-out torque
D. None of the above

The construction of a synchronous motor resembles____________?

A. A series motor
B. An induction motor
C. An alternator
D. A rotary converter

For power factor correction, synchronous motors operate at____________?

A. No-load and greatly over-excited fields
B. No-load and under-excited fields
C. Normal load with minimum excitation
D. Normal load with zero excitation

Which of the following losses is not dissipated by the stator core surface in a synchronous motor?

A. Eddy current losses in the conductors
B. Iron losses in the stator
C. Copper losses in the slot portion of the conductors
D. Windage losses

The size of a synchronous motor decreases with the increase in___________?

A. Flux density
B. Horse power rating
C. Speed
D. All of the above

Which of the following losses, in a synchronous motor, does not vary with load?

A. Windage loss
B. Copper losses
C. Any of the above
D. None of the above

In a synchronous motor, the armature current has large values for____________?

A. High excitation only
B. Low excitation only
C. Both high and low excitation
D. None of the above

The back e.m.f. in the stator of a synchronous motor depends on____________?

A. Number of poles
B. Flux density
C. Rotor speed
D. Rotor excitation

If the field of a synchronous motor is underexcited, the power factor will be_____________?

A. Zero
B. Unity
C. Lagging
D. Leading