Which device is used to measure electrical current in a circuit?

The device used to measure electrical current in a circuit is the ammeter (often referred to as ampermeter). An ammeter is specifically designed to measure the flow of electric charge in amperes (A), providing an understanding of how much current is flowing through a given section of a circuit. It is typically connected in series with the circuit so that all the current passes through it, allowing for an accurate measurement.

In contrast, a voltmeter measures the potential difference (voltage) across two points in an electrical circuit and is connected in parallel. A wattmeter measures power in watts by evaluating both the current in amperes and the voltage in volts, while an ohmmeter is used to measure resistance in ohms. Each of these other devices serves a distinct purpose in electrical measurements but does not measure current directly like the ammeter does.