Category: Polyphase Induction Motors

A. high speed steel
B. stainless steel
C. carbon steel
D. cast iron

A. the motor will run in reverse direction
B. the motor will run at reduced speed
C. the motor will not run
D. the motor will burn

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. iron losses in stator will be negligible as compared to that in rotor
B. iron losses in motor will be neg¬ligible as compared to that in rotor
C. iron losses in stator will be less than that in rotor
D. iron losses in stator will be more than that in rotor

A. synchronous speed
B. below synchronous speed
C. above synchronous speed
D. any of the above

A. motor takes five to seven times its full load current
B. it will pick-up very high speed and may go out of step
C. it will run in reverse direction
D. starting torque is very high

A. it is run on load
B. it is run in reverse direction
C. it is run on voltage higher than the rated voltage
D. e.m.f. is injected in the rotor circuit

A. twice the full load torque
B. 1.5 times the full load torque
C. equal to full load torque

A. it will run in reverse direction
B. it will pick up very high speed and may go out of step
C. motor takes five to seven times its full load current
D. starting torque is very high

A. at the unit value of slip
B. at the zero value of slip
C. at the value of the slip which makes rotor reactance per phase equal to the resistance per phase
D. at the value of the slip which makes the rotor reactance half of the rotor