Correct Answer is: mica is harder than copper

DC Generator MCQ Multiple Choice Questions Answers | Quiz for Practice

Q: 1. In a four-pole D.C. machine

Correct Answer is: alternate poles are north and south

Q: 2. In over compounded generator, full load terminal voltage is

Correct Answer is: more than noload terminal voltage

Q: 3. Armature coil is short circuited by brushes when it lies

Correct Answer is: along neutral axis

Q: 4. Lap winding is composed of

Correct Answer is: any even number of conductors

Q: 5. Wave winding is composed of

Correct Answer is: that even number which is exact multiple of poles + 2

Q: 7. The bearings used to support the rotor shafts are generally

Correct Answer is: ball bearings

Q: 10. Laminations of core are generally made of

Correct Answer is: silicon steel

Q: 13. Which of the following statement about D.C. generators is false ?

Correct Answer is: Equilizing bus bars are used with parallel running of D.C. shunt generators

Q: 16. Armature reaction of an unsaturated D.C. machine is

Correct Answer is: crossmagnetising

Welcome to the DC Generator MCQ Quiz category! Here, you'll find a comprehensive set of multiple-choice questions designed to help students and exam aspirants test their knowledge and prepare effectively.

About DC Generator MCQ Questions

DC Generator MCQs cover a wide range of topics, including the principles of operation, types of DC generators, EMF equation, characteristics, and applications. These questions are crafted to ensure a deep understanding of the fundamental concepts and practical aspects of DC generators.

Why Practice DC Generator Objective Questions?

Practicing DC Generator MCQs offers numerous benefits. It helps you reinforce your understanding of key concepts, improves your problem-solving skills, and prepares you for various exams and interviews. Regular practice ensures that you are well-equipped to tackle questions in school exams, competitive exams, and job interviews.

Who Should Use These MCQs?

Students preparing for school or college exams
Competitive exam aspirants
Candidates preparing for interviews

DC Generator MCQ Questions for Practice

1. In a four-pole D.C. machine

all the four poles are north poles
alternate poles are north and south
all the four poles are south poles
two north poles follow two south poles

2. In over compounded generator, full load terminal voltage is

almost zero
less than noload terminal voltage
more than noload terminal voltage
equal to no-load terminal voltage

3. Armature coil is short circuited by brushes when it lies

along neutral axis
along field axis
in any of the above positions
in none of the above positions

4. Lap winding is composed of

any even number of conductors
any odd number of conductors
that even number which is exact multiple of poles + 2
that even number which is exact multiple of poles

5. Wave winding is composed of

any even number of conductors
any odd number of conductors
that even number which is exact multiple of poles + 2
that even number which is exact multiple of poles

6. The terminal voltage of a D.C. shunt generator drops on load because of all of thefollowing reasons except

armature reaction
armature resistance drop
field weakening due to armature reaction and armature
commutation

7. The bearings used to support the rotor shafts are generally

ball bearings
bush bearings
magnetic bearmgs
needle bearings

8. In a D.C. generator the critical resistance refers to the resistance of

brushes
field
armature
load

9. Brushes of D.C. machines are made of

carbon
soft copper
hard copper
all of above

10. Laminations of core are generally made of

case iron
carbon
silicon steel
stainless steel

11. In D.C. generators, current to the external circuit from armature is given through

commutator
solid connection
slip rings
none of above

12. Which of the following could be lamina-proximately the thickness of laminations of a D.C. machine ?

0.005 mm
0.05 mm
0.5 m
5 m

13. Which of the following statement about D.C. generators is false ?

Compensating winding in a D.C. machine helps in commutation
In a D. C. generator interpoles winding is connected in series with the armaturewinding
Back pitch and front pitch are both odd and approximately equal to the pole pitch
Equilizing bus bars are used with parallel running of D.C. shunt generators

14. In a commutator

copper is harder than mica
mica and copper are equally hard
mica is harder than copper
none of the above

15. The commutator segments are connected to the armature conductors by means of

copper lugs
resistance wires
insulation pads
brazing

16. Armature reaction of an unsaturated D.C. machine is

crossmagnetising
demagnetising
magnetising
none of above

17. A cumulatively compounded long shunt generator when operating as a motor would be

cumulatively compounded long shunt
differentially compounded long shunt
cumulatively compounded short shunt
differentially compounded short shunt

18. In case of D.C. machines, mechanical losses are primary function of

current
voltage
speed
none of above

19. With a D.C. generator which of the following regulation is preferred ?

100% regulation
infinite regulation
50% regulation
1% regulation

20. Armature reaction in a generator results in

demagnetisation of leading pole tip and magnetisation of trailing pole tip
demagnetisation of trailing pole tip and magnetisation of leading pole tip
damagnetising the centre of all poles
magnetising the centre of all poles

21. If brushes of a D.C. generator are moved in order to bring these brushes in magneticneutral axis, there will be

demagnetisation only
cross magnetisation as well as magnetisation
crossmagnetisation as well as demagnetising
cross magnetisation only

22. While applying Flemings right-hand rule to And the direction of induced e.m.f., the thumb points towards

direction of induced e.m.f.
direction of flux
direction of motion of the conductor if forefinger points in the direction of generatede.m.f.
direction of motion of conductor, if forefinger points along the lines of flux

23. In lap winding, the number of brushes is always

double the number of poles
same as the number of poles
half the number of poles
two

24. Which of the following components of a D.C, generator plays vital role for providingdirect current of a D.C. generator ?

Dummy coils
Commutator
Eye bolt
Equilizer rings

25. The e.m.f. generated by a shunt wound D.C. generator is E. Now while pole flux remainsconstant, if the speed of the generator is doubled, the e.m.f. generated will be

E/2
2E
slightly less than E
E

26. The series field of a short-shunt D.C. generator is excited by

external current
armature current
shunt current
load current

27. In a D.C. generator

external resistance = internal char-acteristic - armature reaction
internal characteristic = magnetisation characteristic - ohmic drop
external characteristic = magnetisation characteristic - ohmic drop - armature reaction
magnetisation characteristic = external characteristic

28. The critical resistance of the D.C. generator is the resistance of

field
brushes
armature
load

29. Permeance is the reciprocal of

flux density
reluctance
ampere-turns
resistance

30. A shunt generator running at 1000 r.p.m. has generated e.m.f. as 200 V. If the speedincreases to 1200 r.p.m., the generated e.m.f. will be nearly

150 V
175 V
240 V
290 V