A certain 25-hp three-phase induction motor operates from a 440-V-rms (line-to-line) three-phase...

A certain 25-hp three-phase induction motor
operates from a 440-V-rms (line-to-line) three-phase source. The full-load
speed is 1750 rpm. The motor has a starting torque equal to 200 percent of its
full-load torque when started at rated voltage. For an engineering estimate,
assume that the starting torque of an induction motor is proportional to the
square of the applied voltage. To reduce the starting current of the motor, we
decide to start it with a line-to-line voltage of 220 V. Estimate the starting
torque with this reduced line voltage.