Question

The area of the region covered by the TV broadcast by a TV tower of 100 m height is (Radius of the earth = $6.4\times 10^{6}m$ )

• A. $12.8\pi \times 10^{8}k{m}^2$
• B. $1.28\pi \times 10^{3}k{m}^2$
• C. $0.644\pi \times 10^{3}k{m}^2$
• D. $1.28\pi \times 10^{3}k{m}^2$
• E. $2.56\pi \times 10^{3}k{m}^2$

Answer 1

Answer: (B)

Area of broadcast is
A = $\pi d^2=\pi (2hR)$
Given, $h=100mR=6.4\times 10^{6}m$
$\Rightarrow A=\pi (2\times 100\times 6.4\times 10^6)$
A = $1.28\pi \times 10^{3}k{m}^2$