Electric Current
A complete interactive guide — from the fundamentals of charge flow through Ohm's law, resistance, circuits, and Kirchhoff's rules.
Based on the lecture by P. Makra et al. · Dept. of Medical Physics and Informatics · University of Szeged
Electric potential difference (voltage) between two points creates a potential energy difference, meaning the electric field can do work on a charge. Mobile charged particles move under this influence, and whenever there is a net flow of charge, we say electric current exists.
Convention
By convention, the direction of electric current is the direction in which positive charges move — opposite to actual electron flow in metals.
Current flows from areas of higher electric potential towards regions of lower electric potential.
Direction of Current vs Electron Flow
Analogies
Gravitational Field
Object rolls from higher to lower gravitational potential energy.
Fluid Flow
Fluid flows from higher pressure to lower pressure.
Heat Conduction
Heat flows from higher temperature to lower temperature.
Electric current is the rate at which charges cross a surface.