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

In a step-down transformer, there is a change of 15 A in the load current. This results in change of supply current of_________________?

A. less than 15 A
B. more than 15 A
C. 15 A
D. none of the above

Noise level test in a transformer is a______________?

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

Iron loss of a transformer can be measured by____________?

A. low power factor wattmeter
B. unity power factor wattmeter
C. frequency meter
D. any type of wattmeter

A good voltage regulation of a transformer means________________?

A good voltage regulation of a transformer means
A. output voltage fluctuation from no load to full load is least
B. output voltage fluctuation with power factor is least
C. difference between primary and secondary voltage is least
D. difference between primary and secondary voltage is maximum

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

The size of a transformer core will depend on__________?

A. frequency
B. area of the core
C. flux density of the core material
D. A. and B. both