$\begin{array}{1 1}(a)\;50m\\(b)\;75m\\(c)\;25m\\(d)\;100m\end{array}$

Population density $S=1000 /Km^{2}$

$\Rightarrow 1000\times 10^{-6}m^{-2}$

$\Rightarrow 10^{-3}m^{-2}$

Let $h$ be height of tower, $d$ be radius of coverage, and $R$ the radius of earth $\rightarrow$ $d=\sqrt{2Rh}$

Population covered =$S\pi d^2 = 2\pi RSh$

$10\; \text{Lakhs} = 10 \times 10^5 = 2 \times \pi \times 6400\times 10^3 \times 10^{-3}\times h$

$\Rightarrow h=25m$

Hence (c) is the correct answer.

Ask Question

Tag:MathPhyChemBioOther

Take Test

...