JEE Main2014PhysicsCommunication SystemActual
A transmitting antenna at the top of a tower has a height 32 m and the height of the receiving antenna is 50 m . What is the maximum distance between them for satisfactory communication in line of sight (LOS) mode?
Options
- A45 . 5   km
- B54 . 5   km
- C55 . 4   km
- D455   km
Correct answer
A. 45 . 5   km
Step-by-step solution
Given, Height of transmitting antenna is, h T = 50   m Height of receiving antenna is, h R = 32   m Thus, maximum distance for satisfactory communication will be, d M = 2 R h T + 2 R h R where R is radius of the Earth, d M = 2 R h T + 2 R h R d M = 2 × 64 × 10 5 × 50 + 2 × 64 × 10 5 × 32 d M = 8000 10 + 6400 10 d M = 14400 10   m d M = 45536 . 7   m d M = 45 . 5   km