Which of the following is used to increase the voltage (amplitude) level of an analog signal at the beginning of a long cable run and is measured in decibels (db)?

The correct answer is related to the concept of gain in audio and video signals. Gain refers to the increase in amplitude or voltage level of an analog signal. It is a crucial factor when dealing with long cable runs because signals can degrade due to distance, resulting in a loss of quality and strength. By applying gain at the source of the signal, it ensures that the signal maintains a strong enough level to travel through the cable without significant loss.

Gain is typically measured in decibels (dB), which is a logarithmic unit that provides a convenient way to express the ratio of power or intensity levels. This makes it possible to quantify how much the signal has increased in amplitude. Thus, applying gain effectively at the beginning of a long cable run helps maintain the integrity of the signal as it travels over distance.

While other options may seem relevant, they do not specifically denote the intentional increase of voltage in the same context as gain does. An attenuator, for instance, serves to reduce the level of the signal rather than increase it. Signal boosters might seem similar, but in technical terminology, gain specifically describes the desired increase in a signal’s amplitude.