Q. A TV tower has a height of 100 m. How much population is covered by the TV broadcast if the average population density around the tower is $100\ km^{- 2}$ (radius of the earth$= 6.37 \times 10^{6}$ m)
A) 4 lakh
B) 4 billion
C) 40,000
D) 40 lakh
Explanation
(d) $d = \sqrt{2hR}$
Population covered
$= \pi d^{2} \times$population density
$= 3.114 \times (2 \times 0.1 \times 6.37 \times 10^{3}) \times 1000 \approx 40$ lakh
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.