If the height of the transmitting tower is increased by $30 \%$, then the area covered by it increases by
If the height of the transmitting tower is increased by $30 \%$, then the area covered by it increases by
10\%
$21 \%$
$30 \%$
$60 \%$
Solution
Area covered by a transmission tower of height $h$ is
$\begin{aligned}
& A=2 \pi R h \\
\Rightarrow \quad & A \propto h
\end{aligned}$
So, if height is increased by $30 \%$, area of coverage also increase by $30 \%$.