Practice MCQ Questions and answers on Polyphase Induction Motors Mcqs

A. increases the load torque

B. decreases the starting torque

C. increases the starting torque

D. none of the above

A. increasing slip

B. increasing current

C. both A. and (b)

D. none of the above

A. synchronous speed

B. below synchronous speed

C. above synchronous speed

D. any of the above

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. slip ring motor only but not with squirrel cage induction motor

B. squirrel cage induction motor only but not with slip ring motor

C. squirrel cage as well as slip ring induction motor

D. none of the above

A. initial cost is the main consideration

B. maintenance cost is to be kept low

C. higher starting torque is the main consideration

D. all above considerations are involved

A. slip ring induction motor

B. squirrel cage induction motor

C. both A. and (b)

D. none of the above

A. dependent on the shaft loading

B. dependent on the number of slots

C. slip times the stand still e.m.f. induced in the rotor

D. none 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