The efficiency of a transformer, under heavy loads, is comparatively low because_______________?
Correct answer: A. copper loss becomes high in proportion to the output
- 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
Explanation
Copper loss varies approximately with the square of load current, while output rises roughly in proportion to load current. Therefore, at heavy load the copper-loss fraction increases and efficiency falls.
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