A current is a constant stream of Charge moving in the same direction. This direction is the direction of where the positive charges are going. The number of electrons moving past a certain point on the wire is the current.

Formula

Where:

Length

Conventional Current

Conventional current means current flows from positive to negative. In reality, electrons move negative to positive, but its too much work to change this in science.

Determine Through Cell

Conventional current runs positive to negative

Current Danger

Current is the metric you need to worry about the most. You cannot push 30 amps through a 20 amp wire, or else that wire would break.