A. at no load
B. at 50% full load
C. at 80% full load
D. at full load
Related Mcqs:
- 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 - An ideal transformer will have maximum efficiency at a load such that?
A. copper loss = iron loss
B. copper loss iron loss
D. none of the above - For a transformer, operating at constant load current, maximum efficiency will occur at______________?
A. 0.8 leading power factor
B. 0.8 lagging power factor
C. zero power factor
D. unity power factor - Distribution transformers are generally designed for maximum efficiency around________________?
A. 90% load
B. zero load
C. 25% load
D. 50% load - Which of the following is the main advantage of an auto-transformer over a two winding transformer?
A. Hysteresis losses are reduced
B. Saving in winding material
C. Copper losses are negligible
D. Eddy losses are totally eliminated - The changes in volume of transformer cooling oil due to variation of atmospheric temperature during day and night is taken care of by which part of transformer?
A. Conservator
B. Breather
C. Bushings
D. Buchholz relay - Efficiency of a power transformer is of the order of________________?
A. 100 per cent
B. 98 per cent
C. 50 per cent
D. 25 per cent - In a transformer routine efficiency depends upon_____________?
A. supply frequency
B. load current
C. power factor of load
D. both B. and (c) - 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 - In a transformer the resistance between its primary and secondary is____________?
A. zero
B. 1 ohm
C. 1000 ohms
D. infinite
