An electrical power line, having a total resistance of 2 $\Omega$, delivers 1 kW at 220 V. The efficiency of the transmission line is approximately :
Solution
We know, $\eta = {{{P_{out}}} \over {\left( {{P_{out}} + {P_{loss}}} \right)}} \times 100$
<br><br>Given, P= $vi = {10^3}$<br><br>$\therefore$ $i = {{1000} \over {220}}$ = ${{50} \over {11}}$ A
<br><br>Power $loss = {i^2}R = {\left( {{{50} \over {11}}} \right)^2} \times 2$<br><br>$\therefore$ efficiency $= {{1000} \over {1000 + {i^2}R}} \times 100 = 96\%$
About this question
Subject: Physics · Chapter: Current Electricity · Topic: Ohm's Law and Resistance
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