Electrical Circuit Theory and Technology 6th Edition by John Bird

Exercise 7

The power supplied to a three-phase induction motor is 40 kW and the stator losses are 2 kW. If the slip is 4% determine (a) the rotor copper loss, (b) the total mechanical power developed by the rotor, (c) the output power of the motor if frictional and windage losses are 1.48 kW, and
(d) the efficiency of the motor, neglecting rotor iron loss.