What is the primary function of an amplifier?

An amplifier's primary function is to increase the amplitude of an electrical signal. This amplification is crucial in various applications, as it allows a weak signal, such as that from a microphone or a sensor, to be boosted to a level suitable for further processing or output. For instance, in audio systems, amplifiers boost the weak signals captured from musical instruments or vocals so that they can drive speakers and produce sound that is audible at a desired level.

The correct answer highlights the essence of an amplifier's role in signal processing, emphasizing that its utility lies in enhancing signal strength without altering the original content of the signal. The amplification process enables better performance in communications, audio, and various electronic devices where signal integrity is vital.