Electrical Engineering Mcqs Practice Test

Question 1

Efficiency of a power transformer is of the order of________________?

Accepted Answer

B. 98 per cen

Question 2

Which winding in a transformer has more number of turns ?

Accepted Answer

B. High voltage winding

Question 3

Primary winding of a transformer________________?

Accepted Answer

C. could either be a low voltage or high voltage winding

Question 4

A transformer cannot raise or lower the voltage of a D.C. supply because_______________?

Accepted Answer

C. Faraday’s laws of electromagnetic induction are not valid since the rate of change of flux is zero

Question 5

A transformer transforms__________________?

Accepted Answer

C. power

Question 6

In the transformer following winding has got more cross-sectional area______________?

Accepted Answer

A. Low voltage winding

Question 7

While conducting short-circuit test on a transformer the following side is short circuited?

Accepted Answer

B. Low voltage side

Question 8

Which of the following is not a part of transformer installation ?

Accepted Answer

D. Exciter

Question 9

The purpose of providing an iron core in a transformer is to_____________?

Accepted Answer

C. decrease the reluctance of the magnetic path

Question 10

No-load current in a transformer________________?

Accepted Answer

A. lags behind the voltage by about 75°

Question 11

The efficiency of a transformer will be maximum when_____________?

Accepted Answer

D. copper losses = iron losses

Question 12

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

Accepted Answer

A. 1.7 Wb/m2

Question 13

Sumpner’s test is conducted on transformers to determine_____________?

Accepted Answer

A. temperature

Question 14

The dielectric strength of transformer oil is expected to be______________?

Accepted Answer

B. 33 kV

Question 15

No-load on a transformer is carried out to determine______________?

Accepted Answer

C. magnetising current and loss

Question 16

The path of a magnetic flux in a transformer should have______________?

Accepted Answer

D. low reluctance

Question 17

The no-load current drawn by transformer is usually what per cent of the full-load current ?

Accepted Answer

B. 2 to 5 per cent

Question 18

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

Accepted Answer

D. all of the above

Question 19

A transformer core is laminated to__________?

Accepted Answer

B. reduce eddy current losses

Question 20

In a transformer the energy is conveyed from primary to secondary_________?

Accepted Answer

C. by the flux