A. 60 to 90%
B. 80 to 90%
C. 95 to 98%
D. 99%
A. to reduce the magnetic hum and locking tendency of the rotor
B. to increase the tensile strength of the rotor bars
C. to ensure easy fabrication
D. none of the above
A. changing supply frequency
B. changing number of poles
C. changing winding resistance
D. reducing supply voltage
A. The slip of the motor will be 5%
B. The rotor will not run
C. The rotor will run at very high speed
D. The torque produced will be very large
A. power factor at starting is high as compared to that while running
B. power factor at starting is low as compared to that while running
C. power factor at starting in the same as that while running
A. open-circuit test only
B. short-circuit test only
C. stator resistance test
D. none of the above
A. e.m.f. injection in rotor eueuit
B. Changing the number of poles
C. Cascade operation
D. None of the above