What is the effect of the inverse-square law in radio wave propagation?

The inverse-square law is a fundamental principle in physics that describes how energy, such as radio waves, propagates through space. According to this law, the strength of a signal decreases as the distance from the source increases, specifically following the principle that the intensity diminishes in proportion to the square of the distance from the transmitter. This means that if you double the distance from the source, the strength of the signal becomes one-fourth of its original value.

When evaluating the answer related to the effect of the inverse-square law on radio wave propagation, it accurately reflects that as the distance from the transmitter increases, the signal strength diminishes inversely with the square of that distance. This concept is crucial for understanding how far a radio signal can effectively travel and how obstacles and atmospheric conditions can further influence signal attenuation.

In the context of the other options, they do not adhere to the inverse-square relationship: signal strength does not increase quadratically with distance, nor does it decrease linearly; and it certainly does not remain stable regardless of distance. This highlights the importance of the inverse-square law in practical applications such as telecommunications, where understanding signal propagation is essential for effective system design and operation.