A. 1%
B. 100%
C. 0.5%
D. zero
Related Mcqs:
- 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 - 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 - Slip-rings in a synchronous motor carry____________?
A. direct current
B. alternating current
C. no current
D. all of the above - In case one phase of a three-phase synchronous motor is short-circuited the motor will____________?
A. not start
B. run at 2/3 of synchronous speed
C. run with excessive vibrations
D. take less than the rated load - 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 ratio of starting torque to running torque in a synchronous motor is____________?
A. zero
B. one
C. two
D. infinity - A synchronous motor develops maximum power when load angle is____________?
A. 45°
B. 60°
C. 90°
D. 120° - The maximum speed variation in a 3-phase synchronous motor is____________?
A. 10 per cent
B. 6 per cent
C. 4 per cent
D. 2. per cent
E. zero - The power developed by a synchronous motor will be maximum when the load angle is____________?
A. zero
B. 45°
C. 90°
D. 120° - The power factor of a synchronous motor is better than that of induction motor because
A. stator supply is relieved of responsibility of producing magnetic field
B. mechanical load on the motor can be adjusted
C. synchronous motor runs at synchronous speed
D. synchronous motor has large air gap