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Chapter 2 D.C. MACHINE AS A GENERATOR MCQs

1. . An electrical generator is a machine which converts:

(A) Electrical energy into mechanical energy


(B) Chemical energy into electrical energy


(C) Mechanical energy into electrical energy


(D) Electrical energy into chemical energy




2. . The d.c generator works on the principle of:

(A) Fleming’s rule


(B) Lenz’s law


(C) Faraday’s law


(D) Coulomb’s law




3. . Fleming’s right hand rule is used for:

(A) DC Motors


(B) DC generators


(C) Induction Motors


(D) Transformers




4. . The direction of current in a d.c. generator can be determined by:

(A) Faraday’s Law


(B) Lenz’s law


(C) Fleming’s left hand rule


(D) Fleming’s right hand rule




5. . The induced e.m.f. in a d.c generator depends upon:

(A) No. of poles


(B) All of these


(C) No. of conductors


(D) Flux per pole




6. . Armature current from the DC generator is supplied to the external circuit through:

(A) Commutator


(B) Slip rings


(C) Inter poles


(D) Armature




7. . If slip rings are used instead of commutator in a d.c. generator, then output will be:

(A) Pulsating D.C.


(B) D.C.


(C) Zero


(D) A.C




8. . A well designed d.c. generator has overall efficiency:

(A) 85%


(B) 90%


(C) 95%


(D) 99%




9. . A d.c generator can be used as:

(A) Prime mover


(B) Power pump


(C) Rectifier


(D) Rotating amplifier




10. . A basic (single or simple) loop generator consists of:

(A) 2 Poles


(B) 2 conductors (1 turn)


(C) Both (a) & (b)


(D) 4 Poles and 4 Conductors




11. . A single (or simple) loop generator has carbon brushes:

(A) Any of these


(B) 3


(C) 4


(D) 2




12. . For a lap wound d.c. generator, induced e.m.f. is given by:

(A) 𝜙 Z N P / 60


(B) 𝜙 Z N P / 120


(C) 𝜙 Z N / 60


(D) 𝜙 Z N / 120




13. . For a wave wound d.c. generator, induced e.m.f. is given by:

(A) 𝜙 Z N / 120


(B) 𝜙 Z N P / 120


(C) 𝜙 Z N P / 60


(D) 𝜙 Z N / 60




14. . A lap wound generator consists of 100 conductors, flux per pole is 0.1 Wb and induced e.m.f. is 220 volt, speed of generator will be:

(A) 1200 r.p.m.


(B) 2000 r.p.m.


(C) 1000 r.p.m.


(D) 100 r.p.m.




15. . A d.c. generator whose field winding is supplied from an independent external d.c. source is called:

(A) Separately excited d.c. generator


(B) Self excited d.c. generator


(C) Series generator


(D) Compound generator




16. . A d.c. generator whose field magnet winding is excited by itself is called:

(A) Separately excited d.c. generator


(B) Self excited d.c. generator


(C) Series generator


(D) Compound generator




17. . Field winding of separately excited d.c. generator is excited by:

(A) External d.c. source


(B) External a.c. source


(C) Both (a) & (b)


(D) current itself




18. . Field winding of self excited d.c. generator is excited by:

(A) current itself


(B) External d.c. source


(C) Both (a) & (b)


(D) External a.c. source




19. . Example(s) of self excited d.c. generator is/are:

(A) Series generator


(B) Shunt generator


(C) All of these


(D) Compound generator




20. . A generator in which the field winding is connected parallel to the armature is called:

(A) Shunt generator


(B) Series generator


(C) Differential compound generator


(D) Cumulative compound generator




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