The following test results were obtained from a 3-phase, 20 h.p., 400 V, 50 Hz, 6-pole induction motor. No load: 400V, 10A, power factor 0.8; short-circuit: 200V, 50 A, power factor 0.415. The motor drives a load having constant torque of 175 N m. Estimate the possible percentage reduction in the supply voltage before the motor stalls. Assume that the copper losses are equally divided between the stator and the rotor.