The efficiencies of transformers compared with that of electric motors of the same power are____________?

A. About the same
B. Much smaller
C. Much higher
D. Somewhat smaller

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

A. Unity
B. Lagging
C. Leading
D. Zero

Auto-transformer makes effective saving on copper and copper losses, when its transformation ratio is_________________?

A. Approximately equal to one
B. Less than one
C. Great than one
D. None of the above

If a transformer is switched on to a voltage more than the rated voltage______________?

A. Its power factor will deteriorate
B. Its power factor will increase
C. Its power factor will remain unaffected
D. Its power factor will be zero

Part of the transformer which is most subject to damage from overheating is_____________?

A. Iron core
B. Copper winding
C. Winding insulation
D. Frame or case

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

A. Primary turns to secondary turns
B. Secondary current to primary current
C. Secondary induced e.m.f. to primary induced e.m.f
D. Secondary terminal voltage to primary applied voltage

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

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

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

A. Insulation resistance
B. Copper loss
C. Core loss
D. Total loss

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

A. Copper loss becomes high in proportion to the output
B. Iron loss is increased considerably
C. Voltage drop both in primary and secondary becomes large
D. Secondary output is much less as compared to primary input

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

A. Temperature rise
B. Dielectric strength of oil
C. Voltage ratio
D. Copper loss