Question

A transmitting antenna is at a height of $40m$ and the receiving antenna is at a height of $60m.$ The maximum distance between them for satisfactory communication is nearly

• A. $22.5km$
• B. $27.5km$
• C. $50km$
• D. $25km$

Answer 1

The correct option is C $50km$

The maximum distance for statisfactory communication is given by:

$d_{max}=\sqrt{2R{H}_T}+\sqrt{2R{H}_R}\Rightarrow d_{max}=\sqrt{\frac{2\times 6400\times 40}{1000}}+\sqrt{\frac{2\times 6400\times 60}{1000}}\Rightarrow d_{max}=8\sqrt{8}+8\sqrt{12}=50km$