JEE Main202122 Jul 2021Morning ShiftPhysicsCommunication SystemActual
What should be the height of transmitting antenna and the population covered if the television telecast is to cover a radius of 150 km ? The average population density around the tower is 2000 km - 2 and the value of R e = 6 . 5 × 10 6 m .
Options
- AHeight = 1731   m Population Covered = 1413 × 10 5
- BHeight = 1241   m Population Covered = 7 × 10 5
- CHeight = 1600   m Population Covered = 2 × 10 5
- DHeight = 1800   m Population Covered = 1413 × 10 8
Correct answer
A. Height = 1731   m Population Covered = 1413 × 10 5
Step-by-step solution
Radius covered, r = 2 R H T 150   km = 2 × 6 . 5 × 10 6   m H T 150   km × 10 3 2 = 2 × 6 . 5 × 10 6 H T H T = 1731   m Population covered = π r 2 2000   km - 2 = 3 . 14 × ( 150 ) 2 × 2000 = 1413 × 10 5