Britannica Sources used in this answer

How does the charge of each moving particle affect the current in a wire?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

density current: descent to the ocean floor — density current Diagram showing the behaviour of a density current as it descends to the seafloor.

In the context of physics, the term "density current" refers to fluid motion driven by gravity due to density differences, which is distinct from the flow of electric current in a wire.1

Regarding electric current in a wire, the charge of the moving particles—typically electrons—is a fundamental property that dictates how they respond to an electric field. Because electrons carry a negative charge, they move in the direction opposite to the electric field.234

The current $i$ is defined as the amount of charge crossing a plane per unit of time. While the direction of conventional current is defined as the flow of positive charge, a flow of negative charges (like electrons) in the opposite direction is mathematically equivalent to a positive current in the conventional direction. The magnitude of the current is influenced by the number of charge carriers per unit volume, their drift velocity, and the cross-sectional area of the wire. In materials like semiconductors, both electrons and positively charged "holes" contribute to the total current, with their respective charges and mobilities determining the overall conductivity.24567