Related Post

MCQ of D.C motor page-1MCQ of D.C motor page-2MCQ of D.C motor page-3MCQ of D.C motor page-4Multiple Choice Question (MCQ) of D.C. Machines page-1Multiple Choice Question (MCQ) of D.C. Machines page-2Multiple Choice Question (MCQ) of D.C. Machines page-3Multiple Choice Question (MCQ) of D.C. Machines page-4Multiple Choice Question (MCQ) of D.C. Machines page-5Multiple Choice Question (MCQ) of D.C. Machines page-6Multiple Choice Question (MCQ) of D.C. Machines page-7Multiple Choice Question (MCQ) of D.C. Machines page-8Multiple Choice Question (MCQ) of D.C. Machines page-9Multiple Choice Question (MCQ) of D.C. Machines page-10MCQ of D.C motor page-5MCQ of D.C motor page-6MCQ of D.C motor page-7MCQ of D.C motor page-8MCQ of D.C motor page-9MCQ of D.C motor page-10MCQ of D.C motor page-11MCQ of D.C motor page-12MCQ of D.C motor page-13MCQ of D.C motor page-14MCQ of D.C motor page-15MCQ of D.C motor page-16MCQ of D.C motor page-17MCQ of D.C motor page-18

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

Multiple Choice Question (MCQ) of D.C. Machines page-5


≪ Previous Next ≫

41. In a dc motor, the flux leakage coefficient is typically

a) 0.5 to 0.7
b) 0.8 to 1.0
c) 1.1 to 1.3
d) 1.4 to 1.6

Ans: (c)

42. The direction of rotation of a dc motor can be reversed by reversing the connection to

a) Armature
b) Series field
c) Shunt field
d) Any of the above

Ans: (a)

43. The current flowing in conductors of a dc motor is

a) Ac
b) Dc
c) Ac as well as dc
d) Transient

Ans: (a)

44. The armature reaction in a dc motor is attributed to

a) The effect of magnetic field set up by field current
b) The effect of magnetic field set up by armature current
c) The effect of magnetic field set up by back emf
d) Copper losses in the armature

Ans: (b)

45. When an electric traian is moving down a hill the dc motor acts as

a) Dc series motor
b) Dc shunt motor
c) Dc series generator
d) Dc shunt generator

Ans: (c)

46. If the armature current of a dc motor is increased keeping the field flux constant, then the developed torque

a) Increases proportionately
b) Decreases in reverse proportion
c) Remains constant
d) Increases proportional to the square root of current

Ans: (a)

47. The armature current drawn by a dc motor is proportional to

a) The speed of the motor
b) Flux required in the moor
c) Torque required
d) Voltage applied to the motor

Ans: (c)

48. In a dc motor if the brushes are given a backward shift, then

a) Commutation improves and speed decreases
b) Commutation is unaffected and speed increases
c) Commutation improves and speed increases
d) Commutation worsens and speed decreases

Ans: (c)

49. A dc shunt motor is driving a constant torque load with rated excitation. If the field current is reduced to half, then the speed of the motor will become

a) Half
b) Slightly more than half
c) Double
d) Slightly less than double

Ans: (d)

50. The back emf Vb of a dc motor

a) Opposes the applied voltage
b) Assists the applied voltage
c) Does not influence the applied voltage
d) None of these

Ans: (a)


≪ Previous Next ≫


Related topics :


Recent Post

Multiple Choice Question (MCQ) of Transmission and Distribution page-3:
21. ACSR conductor implies
A) Anodized Core Smooth Run
B) Anode current sinusoidally run
C) Aluminium conductor steel reinforced
D) All conductors surface treated and realigned.

Read more...

Multiple Choice Question (MCQ) of Transmission and Distribution page-2:
11. In overhead transmission lines the effect of capacitance can be neglected when the length of line is less than
A) 80 km
B) 100 km
C) 160 km
D) 200 km.

Read more...

Multiple Choice Question (MCQ) of Transmission and Distribution page-1:
1. Which of the following is not the transmission voltage in India ?
A) 400 kV
B) 264 kV
C) 132 kV
D) 66 kV.

Read more...