If a 400 V, 50 Hz, star connected, 3 phase squirrel cage

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If a 400 V, 50 Hz, star connected, 3 phase squirrel cage induction motor is operated from a 400 V, 75 Hz supply, the torque that the motor can now provide while drawing rated current from the supply

1. reduces
2. increases
3. remains the same
4. increases or reduces depending upon the rotor resistance

Correct Option: A

Given induction motor is designed for 400 V, 50 Hz.
When it is connecetd to 400, 75 Hz supply, then speed for motor increases, as it’s clear from [n = 2ƒ/P] slip of the rotor increased

Torque, T_e =	3	. I₂²	r₂
	ω_s		s

As the slip increases, T_e decreases.