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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-generatorsMCQ-Control-SystemMCQ-Measurementsmcq-of-Generation-power-systemMCQ-of-Induction-MotorMCQ-of-Transmission-DistributionMCQ-of-Electrical-MachinesMCQ-of-Alternator-and-Synchronous-MotorsMCQ-Electric-PowerMCQ-Illumination

MCQ of D.C motor page-3


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21. In the field flux method of speed control

a) Any speed can be attained
b) Speeds above normal speed can be attained
c) Speeds below normal speed can be attained
d) None of these

Ans:(b)

22. Speed of the d.c. motor can be varied by

a) Varying armature resistance
b) Varying supply voltage
c) Either (a) or (b)
d) Varying field current

Ans:(c)

23. Dynamic braking is generally used for

a) Shunt motors
b) Compound motors
c) Series motors
d) All of these

Ans:(d)

24. Stalling current is the maximum value of

a) Load current for which speed is zero
b) Field current for which speed is maximum
c) Load current for which speed is maximum
d) Diverter current for which speed is maximum

Ans:(c)

25. Torque developed in d.c. motor depends on

a) Armature
b) Speed
c) Magnetic field
d) Both (a) and (c)

Ans:(d)

26. As the load is increased, speed of d.c. shunt motor will

a) Increase slightly
b) Reduce slightly
c) Remains constant
d) None of these

Ans:(b)

27. Which method of speed control has minimum efficiency ?

a) Field control method
b) Voltage control method
c) Armature control method
d) None of these

Ans:(c)

28. Field flux of d.c. motor can be controlled to

a) Steady speed
b) Speeds above rated speed
c) Speeds below rated speed
d) Speeds above and below rated speed

Ans:(b)


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