AIPMT PRELIMS2007Physics-Electromagnetic Induction
AIPMT PRELIMS 2007 Physics Transformers MCQ Question
Type: MCQ-numerical-Easy-Class 12
A transformer is used to light a 100 W and 110 V lamp from a 220 V mains. If the main current is 0.5 amp, the efficiency of the transformer is approximately
A
50%
B
90%
C
10%
D
30%
Correct Answer
Option B
Detailed Explanation
The efficiency of a transformer is given by the ratio of output power to input power. Here, the output power is 100 W and the input power is 220 V × 0.5 Å = 110 W. Therefore, efficiency = (100/110) × 100% = 90%.
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