Transformer MCQ Questions: Transformer MCQ With Answer

Transformer MCQ Questions. Electrical Engineering MCQs related to Transformers.

 

Transformer MCQ Questions

 

Which of the following acts as a protection against high voltage surges due to lightning and switching ?

A. Horn gaps
B. Thermal overload relays
C. Breather
D. Conservator

View Answer

A. Horn gaps

 

In a given transformer for given applied voltage losses which remain constant irrespective of load changes are ?

A. hysteresis and eddy current losses
B. friction and windage losses
C. copper losses
D. none of the above

View Answer

A. hysteresis and eddy current losses

 

For given applied voltage, with the increase in frequency of the applied voltage ?

A. eddy current loss will decrease
B. eddy current loss will increase
C. eddy current loss will remain unchanged
D. none of the above

View Answer

C. eddy current loss will remain unchanged

 

A transformer can have zero voltage regulation closer to zero ?

A. on full-load
B. on overload
C. on leading power factor
D. on zero power factor

View Answer

C. on leading power factor

 

Which of the following parts of a transformer is visible from outside ?

A. Bushings
B. Core
C. Primary winding
D. Secondary winding

View Answer

A. Bushings

 

Which of the following insulating materials can withstand the highest temperature safely ?

A. Cellulose
B. Asbestos
C. Mica
D. Glass fibre

View Answer

C. Mica

 

Transformer MCQ Questions

 

The transformer oil should have _______ volatility and _______ viscosity ?

A. low,low
B. high,high
C. low,high
D. high,low

View Answer

A. low,low

 

A no-load test is performed on a transformer to determine ?

A. core loss
B. copper loss
C. efficiency
D. magnetising current
E. magnetising current and loss

View Answer

E. magnetising current and loss

 

For the parallel operation of single phase transformers it is necessary that they should have ?

A. same efficiency
B. same polarity
C. same kVA rating
D. same number of turns on the secondary side

View Answer

B. same polarity

 

An open-circuit test on a transformer is conducted primarily to measure ?

A. insulation resistance
B. copper loss
C. core loss
D. total loss

View Answer

C. core loss

 

Minimum voltage regulation occurs when the power factor of the load is ?

A. unity
B. lagging
C. leading
D. zero

View Answer

C. leading

 

When secondary of a current transformer is open-circuited its iron core will be ?

A. hot because of heavy iron losses taking place in it due to high flux density
B. hot because primary will carry heavy current
C. cool as there is no secondary current
D. none of above will happen

View Answer

A. hot because of heavy iron losses taking place in it due to high flux density

 

Transformer MCQ Questions

 

Which of the following is not a routine test on transformers ?

A. Core insulation voltage test
B. Impedance test
C. Radio interference test
D. Polarity test

View Answer

C. Radio interference test

 

Noise level test in a transformer is a ?

A. special test
B. routine test
C. type test
D. none of the above

View Answer

C. type test

 

Which of the following properties is not necessarily desirable for the material for transformer core ?

A. Low hysteresis loss
B. High permeability
C. High thermal conductivity
D. Adequate mechanical strength

View Answer

C. High thermal conductivity

 

Star star transformers work satisfactorily when ?

A. load is unbalanced only
B. load is balanced only
C. on balanced as well as unbalanced loads
D. none of the above

View Answer

B. load is balanced only

 

The magnetizing current of a transformer is usually small because it has ?

A. small air gap
B. large leakage flux
C. laminated silicon steel core
D. fewer rotating parts

View Answer

A. small air gap

 

Distribution transformers are generally designed for maximum efficiency around ?

A. 90% load
B. zero load
C. 25% load
D. 50% load

View Answer

D. 50% load

 

Transformer MCQ Questions

 

Buchholz’s relay gives warning and protection against ?

A. electrical fault inside the transformer itself
B. electrical fault outside the transformer in outgoing feeder
C. for both outside and inside faults
D. none of the above

View Answer

A. electrical fault inside the transformer itself

 

Gas is usually not liberated due to dissociation of transformer oil unless the oil temperature exceeds ?

A. 50°C
B. 80°C
C. 100°C
D. 150°C

View Answer

D. 150°C

 

The chemical used in breather for transformer should have the quality of ?

A. ionizing air
B. absorbing moisture
C. cleansing the transformer oil
D. cooling the transformer oil

View Answer

B. absorbing moisture

 

In a given transformer for given applied voltage, losses which remain constant irrespective of load changes are ?

A. friction and windage losses
B. copper losses
C. hysteresis and eddy current losses
D. none of the above

View Answer

C. hysteresis and eddy current losses

 

Spacers are provided between adjacent coils ?

A. to provide free passage to the cooling oil
B. to insulate the coils from each other
C. both A. and (b)
D. none of the above

View Answer

A. to provide free passage to the cooling oil

 

The maximum efficiency of a distribution transformer is ?

A. at no load
B. at 50% full load
C. at 80% full load
D. at full load

View Answer

B. at 50% full load

 

Transformer MCQ Questions

 

Natural oil cooling is used for transformers up to a rating of ?

A. 3000 kVA
B. 1000 kVA
C. 500 kVA
D. 250 kVA

View Answer

A. 3000 kVA

 

In a transformer routine efficiency depends upon ?

A. supply frequency
B. load current
C. power factor of load
D. both B. and (c)

View Answer

D. both B. and (c)

 

The degree of mechanical vibrations produced by the laminations of a transformer depends on ?

A. tightness of clamping
B. gauge of laminations
C. size of laminations
D. all of the above

View Answer

D. all of the above

 

The permissible flux density in case of cold rolled grain oriented steel is around ?

A. 1.7 Wb/m2
B. 2.7 Wb/m2
C. 3.7 Wb/m2
D. 4.7 Wb/m2

View Answer

A. 1.7 Wb/m2

 

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