A. under-loaded
B. over-loaded
C. under-excited
D. over-excited
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 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 percentage slip in case of a synchronous motor is____________?
A. 1%
B. 100%
C. 0.5%
D. zero - 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 - In a 3-phase synchronous motor, the negative phase sequence exists when the motor is_______________?
A. supplied with unbalanced voltage
B. under-loaded
C. over-loaded
D. none of the above - In a 3-phase, 4-pole, 50 Hz synchronous motor, the frequency, pole number and load torque all are halved. The motor speed will be____________?
A. 3000 r.p.m.
B. 1500 r.p.m.
C. 750 r.p.m.
D. none of the above
