30. In case of 3-phase induction motors, plugging means A pulling the motor directly on line without a starter B locking of rotor due t...

29. The starting torque of a 3-phase squirrel cage induction motor is A 1.5 times the full load torque B twice the full load torque C ...

28. Which type of bearing is provided in small induction motors to support the rotor shaft? A Cast iron bearings B Bush bearings C Ba...

27. A 3-phase induction motor stator delta connected, is carrying full load and one of its fuses blows out. Then the motor A will continu...

26. Size of a high speed motor as compared to low speed motorfor the same H.P. will be A smaller B bigger C same D any of the above...

25. The power factor of an induction motor under no-load conditions will be closer to A 0.2 leading B 0.2 lagging C unity D none of...

24. In a three-phase induction motor, the number of poles in the rotor winding is always A equal to number of poles in stator B more th...

23. The maximum torque in an induction motor depends on A rotor inductive reactance B square of supply voltage C frequency D all of...

22. If any two phases for an induction motor are interchanged A the motor will burn B squirrel-cage induction motors only C the motor...

21. For which motor the speed can be controlled from rotor side ? A Slip-ring induction motor B Squirrel-cage induction motor C both ...

20. Rotor rheostat control method of speed control is used for A slip ring induction motors only B squirrel-cage induction motors only ...

19. It is advisable to avoid line-starting of induction motor and use starter because A it will pick-up very high speed and may go out of...

18. Stepless speed control of induction motor is possible by which of the following methods ? A Changing the number of poles B Cascade ...

17. The crawling in the induction motor is caused by A improper design of the machine B harmonics develped in the motor C low voltage...

16. In the circle diagram for induction motor, the diameter of the circle represents A running torque B Slip C rotor current D lin...

15. Which of the following methods is easily applicable to control the speed of the squirrel-cage induction motor ? A Rotor rheostat cont...

14. An induction motor is identical to A asynchronous motor B synchronous motor C D.C. compound motor D D.C. series motor Check A...

13. An induction motor with 1500 r.p.m. speed will have A 8 poles B 6 poles C 4 poles D 2 poles Check Answer Correct Answer: C ...

12. The good power factor of an induction motor can be achieved if the average flux density in the air gap is A small B large C absen...

11. Star-delta starting of motors is not possible in case of A low horse power motors B single phase motors C variable speed motors ...