Question:
An electrical power line, having a total resistance of $2 \Omega$, delivers $1 \mathrm{~kW}$ at $220 \mathrm{~V}$. The efficiency of the transmission line is approximately:
Correct Option: , 2
Solution:
$\mathrm{vi}=10^{3}$
$\mathrm{i}=\frac{1000}{220}$
loss $=\mathrm{i}^{2} \mathrm{R}=\left(\frac{50}{11}\right)^{2} \times 2$
efficiency $=\frac{1000}{1000+\mathrm{i}^{2} \mathrm{R}} \times 100=96 \%$