a) Motor runs as a generator b) Motor does not run c) The motor runs an at synchronous speed d) Slip produced is zero Ans: (b)
a) To reduce the magnetic hum b) To reduce the locking tendency of the rotor c) Both (a) and (b) above d) To increase the speed of the motor Ans: (c)
a) Rotor speed b) Synchronous speed c) Slip speed d) Very low speed Ans: (b)
a) Equal to the speed of stator field b) Lower than the speed of stator field c) Higher than the speed of stator field d) Having no relation with the speed of stator field Ans: (b)
a) Its starting torque is high b) It is run against heavy load c) It can not run in reverse direction d) Its starting current is five times or more than its rated current Ans: (d)
a) Negligible b) Very heavy c) Independent of supply frequency d) Independent of supply voltage Ans: (a)
a) Stator input in watts b) Rotor output in watts c) Rotor input in watts d) Shaft output in watts Ans: (c)
a) Voltage applied to stator b) Relative velocity between flux and rotor conductors c) Both (a) and (b) above d) Slip Ans: (c)
a) Natural speed at which a magnetic field rotates b) The speed of a synchronous motor c) The speed of an induction motor at no load d) None of these Ans: (a)
a) Rotor resistance equals rotor reactance b) Rotor resistance is twice the rotor reactance c) Rotor resistance is half the rotor reactance d) Rotor resistance is R2 times the rotor reactance Ans: (a)