197.  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

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198.  The efficiency of a transformer, under heavy load, 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

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199.  A no-load test is performed on a transformer to determine
A. core loss
B. efficiency
C. magnetising current
D. magnetising current and core loss

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200.  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

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201. 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

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202. 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

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203.  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

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