A 10 – hp, 4 pole, 25Hz 3-phase induction motor is taking 9100 watts from the line. Core loss is 29 watts, stator copper loss is 568 watts, rotor copper loss is 445 watts and the friction and windage loss 121 watts. Determine the output torque in newton – meters. a.108.4               b. 112.5 c. 101.2              d. 103.3

A) Although the magnetic field for each phase of a 3-phase induction motor is merely switching back and forth between north and south poles, the resultant magnetic influence from all phases sets up a rotating magnetic field to cut the rotor conductors. a) true b) false B) In a two-pole stator winding of a 3-phase motor, how many revolutions does the rotating tr) magnetic field make in one cycle of the electrical current? a) one b) 60   c) 3600 d) none of the above

A 3-phase, 60 Hz induction motor has two poles. If the slip is 2% at a certain load, determine the synchronous speed, the speed of the rotor and the frequency of the induced e.m.f.'s in the rotor.

In a synchronous machine, if magnetic field of the rotor lags the stator field by a mechanical angle "a": O A. It is only possible in an induction machine O B. It is a generator O C. None of the other choices are correct O D. It is a motor O E. It can't happen in synchronous machines; both fields are in synch