Voltage applied to a material generates an electrical current across the surface of the material. The electrical resistance of the material determines how well or poorly the material will resist the flow of current (how much current can flow across the material).

Current can be predicted using a formula known as Ohm’s Law. Actual current, which may differ from currents predicted by Ohm’s Law calculations, refers to the actual current measured in laboratory tests.

Ohm’s Law + i=V/r

Current (i) in amps equals voltage (V) divided by resistance (r) in ohms (Ω)