What type of electronic device increases the amplitude of electrical signals?

An amplifier is specifically designed to increase the amplitude of electrical signals. It takes a low-level input signal and boosts it to a higher level output, making it essential in various applications such as audio systems, radio communications, and broadcasting. By using active components, such as transistors or operational amplifiers, the device regulates the power from a power supply to enhance the signal without distorting its original form.

The correct answer identifies the core functionality of an amplifier, which is to enhance signal strength, crucial for achieving performance in a wide range of electronic setups. While other electronic devices can operate in signal manipulation or processing, amplifiers are uniquely defined by their purpose of increasing signal amplitudes, making them indispensable in electronics.