AC 3 PHASE INDUCTION MOTOR - Practice Mode

1) Which type of starter is used to start and run the 3 phase slip ring induction motor?

Direct on-line starter Rotor rheostat starter Auto transformer starter Manual star-delta starter

Correct Answer: Rotor rheostat starter

2) What is the purpose of using rotor resistance starter to start 3 phase slip ring induction motor?

Reduce rotor voltage Increase rotor current Increase the starting torque Reduce the power loss

Correct Answer: Increase the starting torque

3) Why external resistance is included in the rotor circuit at starting through 3 phase slipring induction motor starter?

To get high running torque To reduce high starting current To reduce the load current To get increased speed at starting

Correct Answer: To reduce high starting current

4) What is the effect of motor, if the rotor windings in slipring induction motor is open circuited at starting?

Will not run Runs at slow speed Runs at very high speed Runs but not able to pull load

Correct Answer: Will not run

Explanation:

The basic principle on which the transformer works is Faraday's Law of Electromagnetic Induction or mutual induction between the two coils. It works on the alternating current only because an alternating flux is required for mutual induction between the two windings.

5) Which method is used to control the speed of 3 phase induction motor from stator side?

By cascade operation By rotor rheostat control By injecting emf in rotor circuit By changing the applied frequency

Correct Answer: By changing the applied frequency

Previous Question Set Back to Question Sets Next Question Set

Try Another Topic

Try Another Quiz