Which of these components can be used as an electronic switch or amplifier?

The component that can be utilized as both an electronic switch and amplifier is the transistor. Transistors operate by controlling the flow of electrical current, making them integral in modern electronic circuits. In a switching application, a small input current can control a larger output current, effectively turning the circuit on or off. Similarly, in amplification, a transistor takes a small input signal and produces a significantly larger output signal, maintaining the waveform of the input.

Oscillators, while crucial for generating frequency signals, do not switch or amplify signals themselves. Potentiometers serve more as variable resistors and are used to adjust levels in a circuit instead of acting as switches or amplifiers. Voltmeters, designed to measure voltage, do not have the functionality to switch or amplify signals. These distinctions highlight why the transistor is uniquely suited for both switching and amplifying roles within electronic systems.