Which device is commonly used to measure electrical current?

An ammeter is specifically designed to measure electric current flowing through a circuit. It operates by being placed in series with the circuit, allowing the current to pass through it directly. The device typically displays the current in amperes, which is the standard unit of measurement for electric current.

The principle behind an ammeter involves its internal resistance, which is very low to minimize the impact on the circuit being measured. This allows for an accurate representation of the current without significantly altering the circuit’s behavior. Using an ammeter enables technicians and electricians to diagnose issues, assess circuit performance, and ensure that devices operate within their specified electrical ratings.

In contrast, other devices listed serve different purposes. A voltmeter measures the electrical potential difference (voltage) across two points in a circuit and is typically connected in parallel. An ohmmeter measures the resistance of an electric component or circuit and is used independently (not in a live circuit). A power meter measures the total power consumption in a circuit, often incorporating both voltage and current readings. Each of these devices plays a crucial role in electrical diagnostics but is not intended for measuring current directly as an ammeter does.