A 75-kW, 460-V, three-phase, four-pole, 60-Hz, wound-rotor induction motor develops a maximum internal torque of 212 percent at a slip of 16.5 percent when operated at rated voltage and frequency with its rotor short-circuited directly at the slip tings. Stator resistance and rotational losses may be neglected, and the rotor resistance may be assumed to be constant, independent of rotor frequency. Determine

a. The slip at full load in percent.

b. The rotor I2R loss at full load in watts.

c. The starting torque at rated voltage and frequency N · m. If the rotor resistance is now doubled (by inserting external series resistance at the slip rings), determine

d. The torque in N · m when the stator current is at its full-load value.

e. The corresponding slip.