Related Topics

  MCQ of D.C generators page-4  MCQ of D.C generators page-3  MCQ of D.C generators page-2  MCQ of D.C generators page-1

Index

SymbolsTransformerRelayPower-SystemBasic-electricalACSR-ConductorCircuit-BreakerInterview-questions-of-Basic-ElectricityInterview-questions-of-transformerInsulatorCurrent-TransformerMCQMCQ-powersystemThermal-power-stationInterview-questions-of-Power-SystemPower-ElectronicsInterview-questions-of-Underground-CableInterview-questions-of-IlluminationIlluminationMCQ-of-ElectronicsMCQ-of-Basic-ElectricalMCQ-of-Transformers MCQ-of-D.C-motor MCQ-of-D.C-generators

MCQ of D.C generators page-3

21. In a dc generator, sparking between brushes and commutator surface may be due to

a) undercommutation
b) overcommutation
c) to rapid reversal of current
d) any of these

Ans: (d)

22. Commutation is possible in dc machines

a) only when the armature is rotating in the field
b) only when the field is rotation in the armature
c) either (a) or (b)
d) none of these

Ans: (a)

23. Which of the following parts helps the commutation process?

a) compensating winding
b) pole shoes
c) interpoles
d) all of these

Ans: (c)

24. Commutation segments in a dc machine are separated by thin layers of

a) paper
b) PVC
c) Synthetic rubber
d) Mica

Ans: (d)

25.Which winding on dc generators is preferred for generating large current?

a) Retrogressive wave winding
b) Progressive wave winding
c) Lap winding
d) All winding give similar results

Ans: (c)

26. Equalizer rings can be used by

a) Both lap and wave wound armatures
b) Lap wound armatures only
c) Wave wound armatures only
d) None of these

Ans: (b)

27. The function of equalizing ring in lap wound dc generator is

a) To increase the efficiency of the machine
b) To avoid short circuit current
c) To neutralize the armature reaction
d) To help get sparklers commutation

Ans: (d)

28.In a ring wound commutator, the brush width equals the width of

a) One commutator segment and two mica insulations
b) One commutator segment and one mica insulation
c) Two commutator segments and two mica insulations
d) Two commutator segments and one mica insulation

Ans: (b)

29. In a dc machine without any brush shift, the shift of the magnetic natural axes due to armature reaction is

a) In the direction of rotation for the generator and against the direction of rotation for the motor
b) In the direction of rotation for both the generator and the motor
c) Against in the direction of rotation for both the generator and the motor
d) Against the direction of rotation for the generator and in the direction of rotation for the motor

Ans: (a)

30. In a dc machine without interpoles, to get improved commutation, the brush shift angle must be

a) Zero degree
b) Kept constant
c) Varied with change in load
d) None of the above

Ans: (c)

<< Previous Next >>

 

Related topics :



Recent Post

Multiple Choice Question (MCQ) of Electronics page-17:
241. Which of the following statement is true? a) The saturation voltage VCF of silicon transistor is more than germanium transistor.
b) The saturation voltage VCE for germanium transistor is more than silicon transistor.
c) The saturation voltage VCE for silicon transistor is same as that for germanium.
d) The saturation voltage VCE for silicon transistor is lower than germanium transistor.

Read more...

Multiple Choice Question (MCQ) of Electronics page-16:
226. Which of the following statement is correct? a) Inner electrons are always present in the semiconductor.
b) Bound electrons are always present in the semiconductor.
c) Free electrons are always present in the semiconductor.
d) Inner and bound electrons are always present in the semiconductor.

Read more...

Multiple Choice Question (MCQ) of Electronics page-15:
211. The materials whose electrical conductivity is usually less than 1 × 106 mho/m are a) Semiconductors
b) Conductors
c) Insulators
d) Alloys

Read more...

Multiple Choice Question (MCQ) of Electronics page-14:
196. In which of the following device the base resistors are not added in the package but added externally? a) UJT
b) CUJT
c) PUT
d) None of the above

Read more...

Multiple Choice Question (MCQ) of Electronics page-13:
181. The conduction in JEFT is always by the a) Majority carriers
b) Minority carriers
c) Holes
d) Electrons
e) Holes and electrons simultaneously

Read more...


Name :   

Comments: