Question

The height of the antenna is 98 m. The radius of Earth is 6400 km. The area up to which it will transmit signal is:

• A. 3642 km2
• B. 3942 km2
• C. 11200 km2
• D. 22400 km2

Answer 1

Answer: (B)

3942 km2

Answer 2

The correct option is (B): 3942 km2
$r = \sqrt{2Rh}$
Area $= \Pi r^{2} = 2\Pi Rh$
$= 2 \times \frac{22}{7} \times 6400 \times 103 \times 98$
$= 3942.4 \times 106m^{2}$
$= 3942.4 km^{2}$