Related Topics

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

1.Effect of armature flux on the main flux in a d.c. motor is that

a) It makes distribution of the flux density across both sections unequal
b) It inclines lines of force through the air gap such that they do not remain radial.
c) Both (a) and (b)
d) None of these

Ans: (c)

2. For a series motor, field flux is

a) Proportional to temperature
b) Constant
c) Proportional to armature current
d) Inversely proportional to armature current

Ans:(c)

3. Speed of d.c. series motor at no load is

a) 1500 rpm
b) 3000 rpm
c) Infinity
d) Zero

Ans:(c)

4. Field flux is constant in

a) Compound motor
b) Shunt motor
c) Series motor
d) None of these

Ans:(c)

5. Function of the commutator in a d.c. machine is

a) To change alternating voltage to direct voltage
b) To change a.c. to d.c.
c) To improve commutation
d) For easy speed control

Ans:(a)

6. Dummy coil in a d.c. machine is used to

a) For mechanical balance of armature
b) Eliminate armature reaction
c) Eliminate reactance voltage
d) None of these

Ans:(a)

7. If back e.m.f. suddenly disappears in a d.c. motor

a) Motor will start action as a generator
b) Motor will stop
c) Windings will burn due to high armature current
d) Nothing will happen

Ans:(c)

8. Four point in d.c. motor is used

a) To increase the field current
b) Not to affect the current through hold on coil even if any change in field current takes place
c) To increase the field current
d) None of these

Ans:(b)

9. Torque-speed characteristic of a series motor is

a) Parabola
b) Rectangular hyperbola
c) Linear
d) None of these

Ans:(b)

10. Direction of rotation of a d.c. series motor can be changed by interchanging

a) Field terminals
b) Voltage terminals
c) Both (a) and (b)
d) None of these

Ans:(c)

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: