Polyphase Induction Motors Set 1

Block rotor test only ✘ No load test only ✘ Block rotor test and no-load test ✘ Block rotor test, no-load test and stator resistance test ✔

Copper ✘ Carbon ✘ Phosphor bronze ✘ Aluminium ✔

Increasing slip ✘ Increasing current ✘ Both (A) and (B) ✘ None of the above ✔

Squirrel-cage induction motors only ✘ Slip ring induction motors only ✘ Both (A) and (B) ✘ None of the above ✔

External inductance to the rotor ✘ External resistance to the rotor ✘ External capacitance to the rotor ✘ Both resistance and inductance to rotor ✔

Two rotors moving in opposite direction ✘ Two parallel windings in stator ✘ Two parallel windings in rotor ✘ Two series windings in stator ✔

Three-phase transformers ✘ Compound generators ✘ D.C. series motors ✘ Induction motors ✔

0.00% ✘ 0.00% ✘ 0% ✘ 0% ✔

Leakage reactance ✘ Power factor on short circuit ✘ Short-circuit current under rated voltage ✘ All of the above ✔

Will continue running burning its one phase ✘ Will continue running burning its two phases ✘ Will stop and carry heavy current causing permanent damage to its winding ✘ Will continue running without any harm to the winding ✔