What defines electric current in a circuit?

Electric current in a circuit is defined as the rate of flow of charged particles, typically electrons. When a circuit is completed and voltage is applied, it creates an electric field that causes these charged particles to move. The movement of these electrons constitutes an electric current, which is measured in amperes.

This definition emphasizes that current is not merely about the presence of voltage or resistance, but rather represents the dynamic flow of charge. A higher current means that more charged particles are passing a given point in the circuit per unit time.

In contrast, while voltage does play a crucial role in establishing the potential difference that drives the current, it is not the current itself. Similarly, resistance affects how much current flows for a given voltage, known as Ohm's Law, but it does not define the current. The type of material used in the circuit can influence the overall resistance and conductivity but does not define the current in isolation. Thus, focusing on the movement of charged particles provides a clear and accurate definition of electric current.