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.Management Sciences
Category: Transformers
The maximum efficiency of a distribution transformer is____________?
A. at no load
B. at 50% full load
C. at 80% full load
D. at full load
The efficiency of a transformer will be maximum when_____________?
A. copper losses = hysteresis losses
B. hysteresis losses = eddy current losses
C. eddy current losses = copper losses
D. copper losses = iron losses
The transformer lamination’s are insulated from each other by____________?
A. mica strip
B. thin coat of varnish
C. paper
D. any of the above
The value of flux involved m the e.m.f. equation of a transformer is____________?
A. average value
B. r.m.s. value
C. maximum value
D. instantaneous value
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
An ideal transformer is one which has_____________?
A. no losses and magnetic leakage
B. interleaved primary and secondary windings
C. a common core for its primary and secondary windings
D. core of stainless steel and winding of pure copper metal
E. none of the above
The transformer ratings are usually expressed in terms of______________?
A. volts
B. amperes
C. kW
D. kVA
Short circuit test on transformers is conducted to determine____________?
A. hysteresis losses
B. copper losses
C. core losses
D. eddy current losses
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