Current (denoted as I) is a measure of the amount of charge moving through an area at a given time. The SI unit for current is the amp, equal to one coulomb per second. Current is related to resistance (R) and voltage (V) by the formula

$ V=IR $

and to power (P) by

$ P=IV $

Current divided by cross-sectional area is called current density, and is represented by J.

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