AC THREE PHASE MOTOR - Practice Mode

1) Calculate the number of coils per phase per pair of poles of 3 phase motor having 2 pole, 24 slots,12 coils?

1 2 3 4

Correct Answer: 4

2) What is the synchronous speed of a A.C 3 phase induction motor having 6 poles at a frequency of 50 Hertz

800 rpm 1000 rpm 1200 rpm 1440 rpm

Correct Answer: 1000 rpm

Explanation:

Ns=(120 x Frequency)/Number of Poles

Ns=(120×50)/6=1000 RPM

3) Calculate the percentage slip in a 3 phase induction motor having 6 poles with a frequency of 50 Hertz rotating with actual speed of 960 rpm?

0.02 0.03 0.04 0.05

Correct Answer: 0.04

4) What is the rotor frequency of a 3 phase squirrel cage induction motor at the time of starting?

Equal to supply frequency 3 times less than supply frequency 3 times more than supply frequency Root(3) times less than supply frequency

Correct Answer: Equal to supply frequency

5) How the voltage is received in the rotor of induction motor?

Direct connection from stator Due to back emf produced in stator Direct connection to rotor from supply By the transformer action of stator and rotor

Correct Answer: By the transformer action of stator and rotor

Previous Question Set Back to Question Sets Next Question Set

Try Another Topic

Try Another Quiz