Category: Polyphase Induction Motors

A. high inductance arid low resistance
B. low inductance and high resistance
C. low inductance and low resistance
D. high inductance and high resistance

A. Ball bearings
B. Cast iron bearings
C. Bush bearings
D. None of the above

A. 8 poles
B. 6 poles
C. 4 poles
D. 2 poles

A. its power factor goes on decreasing
B. its power factor remains constant
C. its power factor goes on increasing even after full load
D. its power factor goes on increasing up to full load and then it falls again

A. the magnetising current of the rotor will decrease
B. the power factor will decrease
C. speed of motor will increase
D. the windage losses will increase

A. will continue running burning its one phase
B. will continue running burning its two phase
C. will stop and carry heavy current causing permanent damage to its winding
D. will continue running without any harm to the winding

A. rotor current
B. rotor power factor
C. rotor e.m.f.
D. shaft diameter

A. resistance is inserted in the stator
B. reduced voltage is applied to the stator
C. resistance is inserted in the rotor
D. applied voltage perl stator phase is 57.7% of the line voltage

A. high starting torque is required
B. load torque is heavy
C. heavy pull out torque is required
D. all of the above

A. to short circuit the rotor at slip rings
B. to short circuit the starting resistances in the starter
C. to short circuit the stator phase of motor to form star
D. none of the above