Mostly, synchronous motors are of_____________? - PakMcqs

Related Mcqs:

1. A synchronous motor installed at the receiving end substation operates with such an excitation that it takes power at lagging power factor. Now if the applied voltage of the synchronous motor goes down, the power factor of the synchronous motor will___________?

   A. remain same B. go down C. improve D. none of the above...

2. 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...

3. Synchronous motors are generally not self-starting because:

   A. the direction of rotation is not fixed B. the direction of instantaneous torque reverses after half cycle C. startes cannot be used on these machines D. starting winding is not provided on the machines...

4. The standard full-load power factor ratings for synchronous motors are___________?

   A. zero or 0.8 leading B. unity or 0.8 lagging C. unity or 0.8 leading D. unity or zero...

5. Synchronous motors are_____________?

   A. not-self starting B. self-starting C. essentially self-starting D. none of the above...

6. 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...

7. When the rotor speed, in a synchronous machine, becomes more than the synchronous speed during hunting, the damper bars develop_________________?

   A. inductor motor torque B. induction generator torque C. synchronous motor torque D. d.c. motor toque E. none of the above...

8. 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...

9. 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...

10. Which of the following motors is non-self starting ?

    A. D.C. series motor B. synchronous motor C. Squirrel cage induction motor D. Wound round induction motor...