A TV tower has a height of `100 m` . How much population is covered by TV broadcast? Given radius of the earth ` = 6.4 xx 10^(6) m` and average density of population ` = 10^(3) km^(-2)`.

Answer

` 40 lakhs`

Explanation

Here , `h = 100 m = 0.1 km , R = 6.4 xx 10^(6) m`
`= 6.4 xx 10^(3) km`, Average population density ,
`rho = 1000 km^(-2)`.
Radius of the area covered on ground by TV
broadcast is `d = sqrt ( 2R h)`
Area covered by TV broadcast ,
`A = pi d^(2) = pi 2 R h`.
Population covered ` = rho A = rho pi 2 R h`
` = 1000 xx (22)/( 7) xx 2 xx (6.4 xx 10^(3)) xx (0.1)`
`= 40.2 xx 10^(5) ~~ 40 lakh`