NTA Abhyas JEE Main2020PhysicsCommunication SystemPractice
A T.V. tower has a height of 100 m . The population covered by T.V. broadcast is, if the average population density around the tower is 1000 people km - 2 .
Options
- A39.5 × 10 5   units
- B19.5 × 10 5   units
- C29.5 × 10 5   units
- D9.4 × 10 5   units
Correct answer
A. 39.5 × 10 5   units
Step-by-step solution
d = 2 R h N = π d 2 σ = 2 π R h σ = 2 × 3.14 × 6400 × 0.1 × 1000 = 2 × 3.14 × 6.4 × 10 5 = 39.5 × 10 5   units