Electrical Engineering Questions And Answers :: Polyphase Induction Motors: part1

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Electrical Engineering : Polyphase Induction Motors QUESTIONS AND ANSWERS :: part1 : 11 to 15

Following Electrical Engineering Multiple choice objective type questions and answers will help you in BSNL JTO, GATE 2024 and IES 2024 examinations :

11.Which of the following methods is easily applicable to control the speed of the squirrel-cage induction motor ?

By changing the number of stator poles
Rotor rheostat control
By operating two motors in cascade
By injecting e.m.f. in the rotor circuit

12.The frame of an induction motor is usually made of

silicon steel
cast iron

13.An induction motor is identical to

D.C. compound motor
D.C. series motor
synchronous motor
asynchronous motor

14.The injected e.m.f. in the rotor of induction motor must have

zero frequency
the same frequency as the slip fre-quency
the same phase as the rotor e.m.f.
high value for the satisfactory speed control

15.The crawling in the induction motor is caused by

low voltage supply
high loads
harmonics develped in the motor
improper design of the machine

More Polyphase Induction Motors QUESTIONS AND ANSWERS available in next pages

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