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-PowerMCQ-Illumination

MCQ of Transformer page-7


≪ Previous Next ≫

61. Ferrite cores have less eddy current losses than iron losses because ferrites have

a) Low permeability
b) High hysteresis
c) High resistance
d) All of these

Ans: (c)

62. The secondary of transformer is never kept open circuited under actual operating conditions to

a) Avoid high voltage insulation
b) Avoid saturation of core
c) Protect the primary circuit
d) Provide safety to human beings

Ans: (b)

63. The end winding of a power transformer is given extra insulation to protect it against

a) Oil leakage
b) Excessive heating
c) Travelling wave surges on distri-bution lines
d) None of these

Ans: (c)

64. The main reason why open circuit test is performed on the low voltage winding of the transformer is that it

a) Draws sufficiently large no-load current for convenient reading
b) Requires least voltage to perform the test
c) Needs minimum power input
d) Has become customary

Ans: (a)

65. For short circuit and open circuit tests of a transformer, the instru-ments are connected on

a) LV side and HV side respectively
b) HV side and LV side respectively
c) HV side only
d) LV side only

Ans: (b)

66. Two transformers operating in parallel share the load depending on their

a) Efficiency
b) Rating
c) Leakage reactance
d) Per unit impedance

Ans: (d)

67. Incorrect polarity in parallel operation of two transformers results in

a) Open circuit
b) Short circuit
c) Regeneration of power
d) Load sharing proportional to their kVA rating

Ans: (b)

68. In parallel operation of trans-formers, to reduce copper loss

a) They should have zero impedance
b) Their phases should be the same
c) They should have equal turns ratio
d) None of these

Ans: (c)

69. The induction reactance of a trans-former depends on

a) Magnetic flux
b) Leakage flux
c) Magnetomotive force
d) Electromotive force

Ans: (b)

70. When the secondary of the trans-former is loaded, the flux in the transformer constant will

a)Remain same.
b) Be directly proportional to secondary current
c) Be directly proportional to the current drawn by primary winding
d) None of these

Ans: (a)


≪ Previous Next ≫


Related topics :