Q. An 8-pole, 3-phase, 50 Hz induction motor is operating at a speed of 720 rpm. The frequency of the rotor current of the motor in Hz is
✅ Correct Answer: (A)
2
Explanation: given a number of poles = 8. supply frequency is 50 hz. rotor speed is 720 rpm. ns = 120×f÷p=120×50÷8 = 750 rpm. s=ns-nr÷ns = 750 – 720÷750 = .04.