A 100-kW radio station emits EM waves in all directions from an antenna on top of a mountain. What is the intensity of the signal at a distance of 10 km? A)8 × 10−5 W/m² B)8 × 10−6 W/m² C)3 × 10−3 W/m² D)0.8 W/m² E)2.5 × 10−5 W/m²

Question

Quizplus · Accepted Answer

The intensity of the signal is given by the formula I = P/(4πr^2), where P is the power of the radio station, and r is the distance from the antenna. In this case, P = 100 kW and r = 10 km = 10,000 m. Plugging these values into the formula, we get I = 100,000 W/(4π(10,000 m)^2) = 8 × 10−6 W/m^2.

A 100-KW Radio Station Emits EM Waves in All Directions