The ratio of starting torque to running torque in a synchronous motor is____________?

A. Zero
B. One
C. Two
D. Infinity

The induced e.m.f. in a synchronous motor working on leading power factor will be_____________?

A. More than the supply voltage
B. Less than the supply voltage
C. Equal to the supply voltage
D. None of these

Which of the following resistances can be measured by conducting insulation resistance test on a synchronous motor ?

A. Phase to phase winding resistance
B. Stator winding to earthed frame
C. Rotor winding to earthed shaft
D. All of the above

The word “OPF” stands for_________?

A. Overseas pakistan federation
B. Overseas people federation
C. Overseas pakistanis foundation
D. None of these

The speed of a synchronous motor:

A. Increases as the load increases
B. Decreases as the load decreases
C. Always remains constant
D. None of the above

When a 3-phase synchronous generator is supplying a zero power factor lagging load, the armature field affects the main field in the following way

A. Augments it directly
B. Directly opposes it
C. Cross-magnetises it
D. None of the above

If in a synchronous motor, driving mechanical load and drawing current at lagging power factor from constant voltage supply, its field excitation is increased, then its power factor__________?

A. Become more
B. Become less
C. Remain constant
D. None of the above

Change of D.C. excitation of a synchronous motor changes:

A. Applied voltage of the motor
B. Power factor of power drawn by the motor
C. Motor speed
D. None of the these

The mechanical displacement of the rotor with respect to the stator, in polyphase multipolar synchronous motors running at full load, is of the order of_____________?

A. Zero degree
B. Two degrees
C. Five degrees
D. Ten degrees

An important advantage of a synchronous motor over wound round induction motor is that

A. Its power factor may be varied at will
B. Its speed is independent of supply frequency
C. Its speed may be controlled more easily
D. None of the above