Question:medium
A transformer connected to 220 V mains is used to light a lamp of rating 100 W and 110 V. If the primary current is 0.5 A, the efficiency of the transformer is (approximately)
A transformer connected to 220 V mains is used to light a lamp of rating 100 W and 110 V. If the primary current is 0.5 A, the efficiency of the transformer is (approximately)
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Efficiency = Output/Input. Always compute actual power delivered, not rated voltage alone.
Updated On: May 8, 2026
- 60%
- 35%
- 50%
- 90%
- 44%
Show Solution
The Correct Option is D
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