A 6-pole, 50 Hz wound rotor induction motor when supplied at the rated voltage and frequency with slip-ring open-circuited, developed a voltage of 100 V between any two rings. If the rotor is driven by an external means at 1000 rpm opposite to the direction of stator field, the frequency of voltage across slip-rings will be _______ Hz .

A 6-pole, 50 Hz wound rotor induction motor when supplied at the rated

1.	A 6-pole, 50 Hz wound rotor induction motor when supplied at the rated voltage and frequency with slip-ring open-circuited, developed a voltage of 100 V between any two rings. If the rotor is driven by an external means at 1000 rpm opposite to the direction of stator field, the frequency of voltage across slip-rings will be _______ Hz .
A.	50 Hz
B.	100 Hz
C.	300 Hz
D.	None of the above
Answer» C. 300 Hz

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