Final answer:
The dropping off of signal strength over distance is known as damping, which causes a decrease in the amplitude of waves as they propagate. This effect impacts the effective range of radio and electrical signals and is mitigated in part by using high towers for transmission.
Step-by-step explanation:
The phenomenon of signal loss over distance is referred to as damping. It results in a decrease in the amplitude of the wave as it propagates, affecting both electrical circuits and radio waves. In the context of radio waves, both the electric and magnetic fields propagate outward from the source as an electromagnetic wave. When electromagnetic waves are emitted from a source, such as a broadcast antenna, their intensity diminishes according to the inverse square law. This means that doubling the distance from the source of the wave would require a fourfold increase in power for the signal to be received with the same intensity. Radio waves carry communication signals by varying amplitude (AM), frequency (FM), or phase, and regulations are in place to prevent interference between the multitude of electromagnetic signals in our environment.
Whether the wave in question is an electromagnetic wave like those used in radio communication or a sound wave, damping is an important factor that defines the effective range and strength of the signal from its source. High towers, like those depicted for television and mobile phone transmissions, are usually utilized to help overcome some of this signal loss by providing a clearer line of sight over a large area.