Question 40

An electric power line having total resistance of $$2\Omega$$, delivers 1 kW of power at 250 V. The percentage efficiency of transmission line is ____ .

Power delivered = 1 kW = 1000 W at V = 250 V. Current $I = P/V = 4$ A.

Power loss = $I^2 R = 16 \times 2 = 32$ W.

Total power = $1000 + 32 = 1032$ W. Efficiency = $1000/1032 \times 100 = 96.9\%$.

The answer is Option 4: 96.9%.

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