To cover a population of 20 lakh, a transmission tower should a height …… (Radius of earth = 6400 km, population per square km = 1000):

Options

A. 25 m
B. 50 m
C. 75 m
D. 100 m

Answer

B

Explanation

Area of region covered `=pi(2nR)`
In 1 `km^(2)` = 1000 people
`" "1/1000 times 20 times 10^(6)=20 times 10^(6)=A`
`therefore" "20 times 10^(3)=pi(2 times h times 6400)`
`rArr" "h=(20 times 10^(3))/(pi times 2 times 6400) = 50m`