Question

If the height of TV tower is increased by $21\%$ , then the transmission range is enhanced by

• A. $10\%$
• B. $5\%$
• C. $15\%$
• D. $25\%$

Answer 1

Answer: (A)

Range $=\sqrt{2Rh}\Rightarrow$ Range $\propto \sqrt{h}$
Here $h$ increases to $1.21h$
$\therefore$ Enhancement range $\propto {\left(1.21\right)}^{\frac{1}{2}}=1.1$
$\therefore$ Increase $=1.1-1=0.10$
$\therefore \%$ increase $=0.10\times 100=10\%$