What device displays an electrical quantity as a numeric value?

The device that displays an electrical quantity as a numeric value is a meter. Meters are specifically designed to measure various electrical parameters, such as voltage, current, resistance, or frequency, and present these measurements in a clear, numeric format. This allows users to easily read and interpret the data being measured, which is critical for diagnosing problems, verifying circuit functionality, or conducting experiments.

In contrast, a potentiometer is a component used to adjust voltage levels in a circuit but does not display any values itself. A transistor is a semiconductor device commonly used as a switch or amplifier but does not measure or display quantities. Similarly, a relay is an electromechanical switch used to control circuits and does not provide any numerical display of electrical quantities. Each of these other devices serves important functions within electronic circuits but does not fulfill the role of displaying a numeric value for electrical quantities.