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A power transmission line feeds input power at 2300 V to a step down transformer with primary windings having 4000 turns, giving the output power at 230 V. If the current in the primary of the transformer is 5A, and its efficiency is 90 %, the output current would be -
- 20 A
- 40 A
- 45 A
- 25 A
Correct answer: 45 A
Solution
The output current can be calculated using the power conservation principle, considering the efficiency of the transformer. The input power is 2300 V multiplied by 5 A, which equals 11500 W. Given the efficiency of 90%, the output power is 11500 W multiplied by 0.90, resulting in 10350 W. Dividing this by the output voltage of 230 V gives an output current of approximately 45 A.
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