If the whole earth is to be connected by LOS communication using space waves ( no restriction of antenna size or tower height), what is the minimum no of antennas required ? Calculate the tower height of these antennas in terms of earth's radius?

Answer

A, D

Explanation

That can be done by using six antennas,
From above figure, side of triangle `= R + h` Also, altitude of triangle
`=
(sqrt(3))/2xx "side" = R`
`rArr (sqrt(3))/2(R +h) = R`
`rArr (sqrt(3)) (R+h) =2R`
`rArr R+h =2/(sqrt3)R`
`rArr h =2/(sqrt(3)) R- R~~ 0.15 R`.
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