Electrical Engineering Mcqs Practice Test

Question 1

During open circuit test of a transformer:

Accepted Answer

A. primary is supplied rated voltage

Question 2

The voltage transformation ratio of a transformer is equal to the ratio of_______________?

Accepted Answer

C. secondary induced e.m.f. to primary induced e.m.f

Question 3

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

Accepted Answer

E. magnetising current and loss

Question 4

Which type of winding is used in 3 phase shell-type transformer?

Accepted Answer

B. Sandwich type

Question 5

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

Accepted Answer

C. core loss

Question 6

The transformer lamination’s are insulated from each other by____________?

Accepted Answer

B. thin coat of varnish

Question 7

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

Accepted Answer

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

Question 8

The efficiency of a transformer, under heavy loads, is comparatively low because_______________?

Accepted Answer

A. copper loss becomes high in proportion to the output

Question 9

The maximum load that a power transformer can carry is limited by its________________?

Accepted Answer

C. voltage ratio

Question 10

The hum in a transformer is mainly attributed to______________?

Accepted Answer

C. magnetostriction

Question 11

Which of the following is the most likely source of harmonics in a transformer ?

Accepted Answer

D. Core saturation

Question 12

If a transformer is continuously operated the maximum temperature rise will occur in_______________?

Accepted Answer

B. windings

Question 13

Iron loss of a transformer can be measured by____________?

Accepted Answer

A. low power factor wattmeter

Question 14

Which of the following loss in a transformer is zero even at full load ____________?

Accepted Answer

B. Friction loss

Question 15

Negative voltage regulation is indicative that the load is___________?

Accepted Answer

A. capacitive only

Question 16

Helical coils can be used on___________________?

Accepted Answer

A. low voltage side of high kVA transformers

Question 17

If the supply frequency to the transformer is increased,”the iron loss will__________?

Accepted Answer

C. increase

Question 18

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

Accepted Answer

C. Radio interference test

Question 19

An ideal transformer will have maximum efficiency at a load such that?

Accepted Answer

A. copper loss = iron loss

Question 20

A transformer can have zero voltage regulation at______________?

Accepted Answer

A. leading power factor