Electric Current

Current is the rate of flow of charge.

I =

ΔQ Δt

Usually the particles moving in an electrical circuit are the free conduction electrons in the metal wiring and in the electrical components (metals or semiconductors). In an electrolyte the particles are ions.Current is measured in amperes or amps (A).1 ampere is the movement of 1 coulomb of charge per second.For a current to occur the conduction electrons must experience an electric force to move through the metal.The electrons in a circuit are usually attracted to the positive terminal of a cell or power source.Current is measured with an ammeter placed in series with the components.The ammeter must have negligible resistance.