Ans[ 0.242] An 8-pole, 50HZ, 3-phase slip ring induction motor has an effective rotor resistance of torque. 0.072/phase. Its stalling speed is 630 r.p.m. How much resistance must be inserted per phase to obtain the maximum torque at starting? Ignore the magnetizing current and stator leakage impedance. Ans[ 0,3721

Ans[ 0.242] An 8-pole, 50HZ, 3-phase slip ring induction motor has an effective rotor resistance of torque. 0.072/phase. Its stalling speed is 630 r.p.m. How much resistance must be inserted per phase to obtain the maximum torque at starting? Ignore the magnetizing current and stator leakage impedance. Ans[ 0,3721

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter35: Harmonics 916

Section: Chapter Questions

Problem 3RQ: Would a positive-rotating harmonic or a negative-rotating harmonic be more harmful to an induction...

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Would a positive-rotating harmonic or a negative-rotating harmonic be more harmful to an induction motor? Explain your answer.
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L-1). The 3-phase wound-rotor induction motor has .... . a) high starting torque b) low starting current c) both "a" and "b" d) neither "a" nor "b" L-2). The 3-phase wound-rotor induction.........a) motor has a wire wound rotor b) motor's rotor can be connected to an external resistive load by way of slip rings and brushes c) motor requires more maintenance than the 3-phase squirrel-cage induction motor d) all of the above L-3). The 3-phase wound-rotor induction motor's rotor circuit's resistance should be adjusted so it is__________ during starting. a) low b) high c) either "a" or "b" d) neither "a" nor "b" L-4). Will a 3-phase wound-rotor induction motor start with no external circuit connected to its rotor leads? a) yes b) no