The speed of a squirrel-cage induction motor can be controlled by all of the following except_____________?

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. windage losses
B. copper losses
C. transformation ratio
D. power scale of circle diagram

A. reduce windage losses
B. reduce eddy currents
C. reduce accumulation of dirt and dust
D. reduce magnetic hum

A. three phase transformers
B. compound generators
C. D.C. series motors
D. induction motors

A. inadequate motor wiring
B. poorely regulated power supply
C. any one of the above
D. none of the above

A. D.C. series motor
B. D.C. shunt motor
C. universal motor
D. none of the above