A 3-phase motor is driving at constant torque load of 1 pu at 5% slip. It has a maximum torque of 2 pu at 10% slip. Torque-speed variation in stable zone is assumed to be linear. For the stable operation of the motor, the minimum pu supply voltage is approximately _______ .

A 3-phase motor is driving at constant torque load of 1 pu at 5% slip.

1.	A 3-phase motor is driving at constant torque load of 1 pu at 5% slip. It has a maximum torque of 2 pu at 10% slip. Torque-speed variation in stable zone is assumed to be linear. For the stable operation of the motor, the minimum pu supply voltage is approximately _______ .
A.	1.72
B.	3.707
C.	0.707
D.	7.07
Answer» D. 7.07

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A 3-phase motor is driving at constant torque load of 1 pu at 5% slip. It has a maximum torque of 2 pu at 10% slip. Torque-speed variation in stable zone is assumed to be linear. For the stable operation of the motor, the minimum pu supply voltage is approximately _______ .

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