How does the average velocity of charge carriers affect electric current?

In physics, electric current is defined as the rate at which electric charge passes a given point. When considering a conductor with a cross-sectional area $A$ containing $n$ free charge carriers per unit volume, each with a charge $q$, the current $i$ is directly proportional to the average velocity $v$ of those carriers.1

This relationship is expressed by the fact that the current is the amount of charge crossing a plane transverse to the conductor per unit time. As the average velocity—often referred to as drift velocity—increases, more charge carriers pass through a given cross-section in a specific time interval, thereby increasing the total current. In metallic conductors, this velocity is typically limited by collisions between the charge carriers and the material's internal structure, a process that also generates heat.12

The flow of current per unit area is known as current density, which is also directly influenced by the average velocity of the charge carriers.1