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Answer: a Explanation: It is true because as one of the phase is missing, it will lead to decrease in speed assuming machine was providing the rated load. 11. Due to the line to ground fault, phase ‘a’ in the induction motor phase supply gets cut, then machine a) continues to run with excessive supply current b) continues to run with reduced slip c) stalls d) all of the mentioned View Answer Answer: a Explanation: It continues to run at lowered speed but with increased current. 12. For 3-phase induction motor, as load increases from no load towards the full load, a) power factor improves b) power factor remains same c) power factor varies linearly d) power factor increases till 40% load and then decreases View Answer Answer: a Explanation: Overall during the operation power factor improves as the reactance reduces and the power factor angle reduces. 13.For 3-phase induction motor, as load increases from no load towards the full load, torque _______ slip. a) increases in proportion to b) decreases in proportion to c) remains constant to d) increases hyperbolically to View Answer Answer: a Explanation: For the lower slip, torque will increase proportionally to the slip as verified by the torque slip characteristic. 14. As a 3-phase induction motor, as load increases from no load towards the full load, A. power factor improves B. torque increases C. air gap flux falls steeply a) A, B b) B, C c) A, B, C d) A,C View Answer Answer: a Explanation: Air gap flux increases as the load increase. 15. Torque-slip characteristic of an induction motor is linear in the smaller slip values, because
