Polyphase Induction Motors

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

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

A. double cage rotor
B. wound rotor
C. short-circuited rotor
D. any of the above

A. 730 r.p.m.
B. 960 r.p.m.
C. 1440 r.p.m.
D. 2880 r.p.m.

A. stall after sometime
B. stall immediately
C. continue to run at lower speed without damage
D. get heated and subsequently get damaged

A. Ball bearings
B. Cast iron bearings
C. Bush bearings
D. None of the above

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

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. in the opposite direction as the direction of the rotating field
B. in the same direction as the direction of the field
C. in any direction depending upon phase squence of supply

A. its power factor goes on decreasing
B. its power factor remains constant
C. its power factor goes on increasing even after full load
D. its power factor goes on increasing up to full load and then it falls again