Question

A $TV$ transmission tower has a height of $240m$. Signals broadcast from this tower will be received by line of sight communication at a distance of (Radius of earth $=6.4\times 10^{6}m$)

• A. $100km$
• B. $110km$
• C. $55km$
• D. $120km$

Answer 1

Answer: (C)

Here, $h=240m$, $R=6.4\times 10^{6}m$
The maximum distance on earth from the transmitter upto which a signal can be received is
$d=\sqrt{2Rh}=\sqrt{2\times \left(6.4\times 10^6\right)\times 240}$
$=55.4\times 10^{3}m=55.4km$