Question

If an AM radio transmitter broadcasts 50.0 kW of power uniformly in all directions, what is the intensity 30.0 km away?

a) 1.23 μW/m²
b) 2.47 μW/m²
c) 4.93 μW/m²
d) 9.87 μW/m²

Answer 1

The intensity of the AM radio transmitter 30.0 km away is 1.23 μW/m².

Step-by-step explanation:

The intensity of an AM radio transmitter at a distance of 30.0 km away can be calculated using the formula:
Intensity = Power / (4 * pi * distance^2)

Given that the power of the transmitter is 50.0 kW and the distance is 30.0 km, we can convert the units to watts and meters respectively and calculate:

Intensity = (50,000 W) / (4 * pi * (30,000 m)^2)

Simplifying this equation gives an intensity of 1.23 μW/m². Therefore, option (a) is the correct answer.