6. A synchronous motor can be used as a synchronous capacitor when it is (d) over-excited (a) under-loaded (b) over-loaded (c) under-excited 7. Synchronous motor always runs at (a) the synchronous speed (b) less than synchronous speed (e) both the speed and rotor flux (c) more than synchronous speed (d) none of the above 8. Change of D.C. excitation of a synchronous motor changes (a) applied voltage of the motor (c) power factor of power drawn by the motor (b) motor speed(d) any of the above (e) all of the above 9. The maximum value of torque that a synchronous motor can develop without losing its synchronism, is known as (a) slip torque (b) pull-out torque (c) breaking torque (d) synchronizing torque 10. The maximum power developed in a synchronous motor will depend on (a) the rotor excitation only (b) the supply voltage only (d) the rotor excitation, supply voltage and maximum value of coupling angle (90°) (c) the rotor excitation and supply volt-age both

6. A synchronous motor can be used as a synchronous capacitor when it is (d) over-excited (a) under-loaded (b) over-loaded (c) under-excited 7. Synchronous motor always runs at (a) the synchronous speed (b) less than synchronous speed (e) both the speed and rotor flux (c) more than synchronous speed (d) none of the above 8. Change of D.C. excitation of a synchronous motor changes (a) applied voltage of the motor (c) power factor of power drawn by the motor (b) motor speed(d) any of the above (e) all of the above 9. The maximum value of torque that a synchronous motor can develop without losing its synchronism, is known as (a) slip torque (b) pull-out torque (c) breaking torque (d) synchronizing torque 10. The maximum power developed in a synchronous motor will depend on (a) the rotor excitation only (b) the supply voltage only (d) the rotor excitation, supply voltage and maximum value of coupling angle (90°) (c) the rotor excitation and supply volt-age both

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter32: Three-phase Motors

Section: Chapter Questions

Problem 10RQ: Name three characteristics that make the synchronous motor different from an induction motor.

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