Question i (25 marks)1- If Ns and N are the speeds of rotating field and rotor respectively, then ratio rotor input/rotor outpuis equal toB- Ns/N C- Ns-N(A- N/Ns2- At starting, rotor reactance of a 3-phase induction motor is(A- SmallD- N-Ns)B- Equal to C- Large D- None of the above)as compared to rotor resistance.3- An eight-pole wound rotor induction motor operating on 60 Hz supply is driven at 1800 rpm by a primemover in the opposite direction of revolving magnetic field. The frequency of rotor current is(A-T20 Hz- B- 180 Hz C- 160 Hz D- 200 Hz)4- The rotor power output of a 3-phase induction motor is 30 KW and corresponding slip is 4%. The rotorcopper loss will beB- 250 Watt(A-625 WattC- 1000 WattD- 1250 Watt)5- The effect of increasing load on a synchronous motor running with normal excitation is toB- Decrease 1, but increase p.f.A- Increase both its 1, and p.f.C- Increase I. but decrease p.f.D- Decrease both its I, and p.f.6- When load on a synchronous motor is increased, its armature currents in increased provided it isA- Normally-excited B- Over-excitedC- Under-excitedD- All of the above

Answered: Image /qna-images/answer/2e15fc2a-7775-47ab-a191-17e401676908.jpg

Question i (25 marks) 1- If Ns and N are the speeds of rotating field and rotor respectively, then ratio rotor input/rotor outpu is equal to B- Ns/N C- Ns-N (A- N/Ns D. N-Ns) 2- At starting, rotor reactance of a 3-phase induction motor is (A- Small as compared to rotor resistance. B- Equal to C- Large D- None of the above). 3. An eight-pole wound rotor induction motor operating on 60 Hz supply is driven at 1800 rpm by a prime mover in the opposite direction of revolving magnetic field. The frequency of rotor current is B- 180 Hz C- 160 Hz D- 200 Hz) (A-T20 Hz 4- The rotor power output of a 3-phase induction motor is 30 KW and corresponding slip is 4%. The rotor copper loss will be B- 250 Watt (A-625 Watt C- 1000 Watt D- 1250 Watt) 5- The effect of increasing load on a synchronous motor running with normal excitation is to A- Increase both its 1, and p.f. B- Decrease 1, but increase p.f. C- Increase 1. but decrease p.f. D- Decrease both its I, and p.f. 6- When load on a synchronous motor is increased, its armature currents in increased provided it is A- Normally-excited B- Over-excited C- Under-excited D- All of the above

Question i (25 marks) 1- If Ns and N are the speeds of rotating field and rotor respectively, then ratio rotor input/rotor outpu is equal to B- Ns/N C- Ns-N (A- N/Ns D. N-Ns) 2- At starting, rotor reactance of a 3-phase induction motor is (A- Small as compared to rotor resistance. B- Equal to C- Large D- None of the above). 3. An eight-pole wound rotor induction motor operating on 60 Hz supply is driven at 1800 rpm by a prime mover in the opposite direction of revolving magnetic field. The frequency of rotor current is B- 180 Hz C- 160 Hz D- 200 Hz) (A-T20 Hz 4- The rotor power output of a 3-phase induction motor is 30 KW and corresponding slip is 4%. The rotor copper loss will be B- 250 Watt (A-625 Watt C- 1000 Watt D- 1250 Watt) 5- The effect of increasing load on a synchronous motor running with normal excitation is to A- Increase both its 1, and p.f. B- Decrease 1, but increase p.f. C- Increase 1. but decrease p.f. D- Decrease both its I, and p.f. 6- When load on a synchronous motor is increased, its armature currents in increased provided it is A- Normally-excited B- Over-excited C- Under-excited D- All of the above

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

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