What is an amplifier?

An amplifier is defined as a combination of electronic components that works to increase a signal's power, voltage, or current. This process is crucial in various applications, especially in the field of electrophysiology, including EEG. In an EEG setting, amplifiers enhance the small electrical signals generated by neuronal activity, making them strong enough to be accurately recorded and analyzed.

The ability to amplify these signals is essential because the electrical activity of the brain generates very small voltages that must be increased to be interpretable. Without amplification, these signals may be lost among background noise or be too weak to analyze effectively. Thus, option B accurately captures the fundamental function of an amplifier in both general electronics and its specific application in EEG technology.