Electric Current
Definition
The flow of electric charge — how many coulombs pass a point every second.
Symbol: · Unit: ampere (A)
Technical definition
The rate of charge flow, I = Q/t, measured in amperes. In metals it is a slow drift of electrons; conventional current is defined as flowing from positive to negative, opposite the electron motion.
Example
A phone charger delivering 2 A pushes 2 coulombs of charge through the cable every second — about 12.5 quintillion electrons per second, even though each electron creeps along slowly.
Current is not the speed of electrons. Individual electrons drift through a wire at mere millimeters per second — yet the light turns on instantly, because the electric field signal races through at near light speed, like a push traveling down a packed line of people. Confusing drift speed with signal speed makes circuits seem impossible.