What is electric current?
Electric current is the rate at which electric charge passes a cross-section, measured in amperes.
How it works and key principles
Mechanism and measurement: Electrons usually carry charge in metals, while ions carry it in solutions. Voltage can drive charge through a circuit and resistance limits current. Ohm’s law describes the voltage-current-resistance relation under suitable conditions, but not every component behaves linearly.
Evidence, examples and limits
Power and safety: Electrical power is related to voltage times current; the same current at different voltages means different power. Alternating current reverses direction periodically, whereas direct current flows in one direction. Current through the body can be dangerous; electrical safety matters especially around moisture and damaged wiring.