At what height is the transmitting antenna to be placed to make a TV transmission up to a distance of 32 km? The radius of earth = `6.4 xx 10^(6)` m.

Explanation

Given radio horizon,
d = 32 km = 32 `xx 10^(3)` m
Let the transmitting antenna be placed at height h.
We know, `" " d = sqrt(2Rh)`
or, `" " h = (d^(2))/(2R) = ((32xx 10^(3))^(2))/(2 xx 6.4 xx 10^(6)) = 80 m`