What measurement unit is used to express electrical current?

The unit used to express electrical current is the Ampere, often abbreviated as "A." The Ampere measures the flow of electric charge in a circuit, specifically indicating how much charge passes a given point within a circuit per unit time. One Ampere equals one coulomb of charge passing through a point in a circuit in one second.

Other units mentioned in the choices serve different purposes in the field of electricity and electronics. The Volt measures electrical potential or voltage, indicating the force that drives electric current through a circuit. The Ohm measures resistance, quantifying how much a material opposes the flow of electric current. The Watt represents power, which is the rate at which electrical energy is transferred or converted and can be calculated using current and voltage.

Understanding these units is crucial in electrical and electronic work, as each plays a distinct role in the behavior and characteristics of electrical circuits.