A. high loads
B. low voltage supply
C. improper design of machine
D. harmonics developed in the motor
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 - Temperature of the stator winding of a three phase induction motor is obtained by___________?
A. resistance rise method
B. thermometer method
C. embedded temperature method
D. all above methods - 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 - A 3-phase 440 V, 50 Hz induction motor has 4% slip. The frequency of rotor e.m.f. will be____________?
A. 200 Hz
B. 50 Hz
C. 2 Hz
D. 0.2 Hz - In case the air gap in an induction motor is increased____________?
A. the magnetising current of the rotor will decrease
B. the power factor will decrease
C. speed of motor will increase
D. the windage losses will increase - The maximum torque in an induction motor depends on___________?
A. frequency
B. rotor inductive reactance
C. square of supply voltage
D. all of the above - The ‘cogging’ of an induction motor can be avoided by____________?
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) - 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 - The stating torque of the slip ring induction motor can be increased by adding__________?
A. external inductance to the rotor
B. external resistance to the rotor
C. external capacitance to the rotor
D. both resistance and inductance to rotor - The torque of a rotor in an induction motor under running condition is maximum__________?
A. at the unit value of slip
B. at the zero value of slip
C. at the value of the slip which makes rotor reactance per phase equal to the resistance per phase
D. at the value of the slip which makes the rotor reactance half of the rotor
