Question

In the transmission of power the voltage of power generated at the generating stations is stepped up from $11$kV to $132$kV before it is transmitted. Why?

Answer 1

Power loss in the cable during transmission $P=I^{2}R$

where $I=\frac{P}{V}$

$⟹$ $P=\frac{P^2}{V^2}R$

Since $P$ and $R$ are fixed, thus $P\propto \frac{1}{V^2}$

So, power loss is inversely proportional to the square of voltage.

Hence, voltage of power generated is increased from $11kV$ to $132kV$ before transmission so as to reduce the power loss.