Question:
A transmitting antenna at top of a tower has a height of $50 \mathrm{~m}$ and the height of receiving antenna is $80 \mathrm{~m}$. What is range of communication for Line of Sight (LoS) mode ?
[use radius of earth $=6400 \mathrm{~km}$ ]
Correct Option: , 4
Solution:
$\mathrm{d}_{\mathrm{t}}=\sqrt{2 \mathrm{Rh}_{1}}+\sqrt{2 \mathrm{Rh}_{2}}$
$=\sqrt{2 \mathrm{R}}\left(\sqrt{\mathrm{h}_{1}}+\sqrt{\mathrm{h}_{2}}\right)$
$=\left(2 \times 6400 \times 10^{3}\right)^{1 / 2}(\sqrt{50}+\sqrt{80})$
$=3578(7.07+8.94)$
$=57.28 \mathrm{Km}$