A radio antenna broadcasts a 1.0 MHz radio wav e with 21 kW of power. Assume that the radiation is emitted uniformly in all directions. What is the waves intensity 25 km from th…

Question

asked Oct 12, 2021 176k views

1 Answer

Koray Birand · Answer 1 · 2021-10-17T01:17:10+0000

Answer:

$I=2.67* 10^(-6)\ W/m$

Step-by-step explanation:

Given that,

Frequency of a radio antenna is 1 MHz

Power, P = 21 kW

We need to find the the waves intensity 25 km from the antenna . The object emits intenisty evenly in all direction. It can be given by :

$I=(P)/(4\pi r^2)\\\\I=(21* 10^3)/(4\pi (25000)^2)\\\\I=2.67* 10^(-6)\ W/m$

So, the wave intensity 25 km from the antenna is
$2.67* 10^(-6)\ W/m$ .