1. A star connected 15 hp, 400 V, six pole, 50 Hz wound rotor induction motor has a stator to rotor turns ratio of 5 : 3. The rotor winding

is also star connected. If the motor is connected to the rated voltage source at 50 Hz and the motor runs at 960 rpm.Determine: a) The operating slip of the motor. b) The induced voltage in the rotor winding per phase and its frequency. c) Speed (rpm) of the rotor field BR w.r.t the (i) rotor, (ii) stator. If the stator winding is short-circuited and the power supply is connected to the rotor winding while the motor runs at 970 rpm, determine: d) The direction of rotation of the motor w.r.t to the rotating magnetic field. e) Induced voltage in the stator winding per phase and its frequency.