A. proper ventilation
B. using DOL starter
C. auto-transformer starter
D. having number of rotor slots more or less than the number of stator slots (not equal)
Related Mcqs:
- The crawling in the induction motor is caused by____________?
A. low voltage supply
B. high loads
C. harmonics develped in the motor
D. improper design of the machine
E. none of the above - The term ‘cogging’ is associated with___________?
A. three phase transformers
B. compound generators
C. D.C. series motors
D. induction motors - Slip ring motor is preferred over squirrel cage induction motor where___________?
A. high starting torque is required
B. load torque is heavy
C. heavy pull out torque is required
D. all of the above - The efficiency of an induction motor can be expected to be nearly____________?
A. 60 to 90%
B. 80 to 90%
C. 95 to 98%
D. 99% - Stepless speed control of induction motor is possible by which of the following methods ?
A. e.m.f. injection in rotor eueuit
B. Changing the number of poles
C. Cascade operation
D. None of the above - If an induction motor with certain ratio of rotor to stator slots, runs at 1/7 of the normal speed, the phenomenon will be termed as____________?
A. humming
B. hunting
C. crawling
D. cogging - In an induction motor the relationship between stator slots and rotor slots is that_____________?
A. stator slots are equal to rotor slots
B. stator slots are exact multiple of rotor slots
C. stator slots are not exact multiple of rotor slots
D. none of the above - Which is of the following data is required to draw the circle diagram for an induction motor ?
A. Block rotor test only
B. No load test only
C. Block rotor test and no-load test
D. Block rotor test, no-load test and stator resistance test - What will happen if the relative speed between the rotating flux of stator and rotor of the induction motor is zero ?
A. The slip of the motor will be 5%
B. The rotor will not run
C. The rotor will run at very high speed
D. The torque produced will be very large - The torque developed by a 3-phase induction motor least depends on__________?
A. rotor current
B. rotor power factor
C. rotor e.m.f.
D. shaft diameter
