78. Insertion of resistance in the stator of an induction motor
A. increases the load torque
B. decreases the starting torque
C. increases the starting torque
D. none of the above
79. An induction motor is identical to
A. D.C. compound motor
B. D.C. series motor
C. synchronous motor
D. asynchronous motor
80. The starting torque of a 3-phase squirrel cage induction motor is
A. twice the full load torque
B. 1.5 times the full load torque
C. equal to full load torque
D. none of the above
81. In induction motor, percentage slip depends on
A. supply frequency
B. supply voltage
C. copper losses in motor
D. none of the above
82. The efficiency of an induction motor is than that of a transformer.
A. lower
B. higher
C. either of the above
D. none of the above
83. If the rotor circuit of a squirrel cage induction motor is open, the rotor will
A. run at very high speed
B. run at very low speed
C. make noise
D. not run
84. The advantage of a slip-ring induction motor over a squirrel cage induction motor is that
A. it has higher efficiency
B. it has higher power factor
C. it can be started with the help of rotor resistance stater
D. none of the above
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