Original: The mathematical equation that describes this relationship is: where V is the potential difference measured across the resistance in units of volts; I is the current through the resistance in units of amperes and R is the resistance of the conductor in units of ohms.
Simplified: This relation is shown in the following formula: where I is the current in amperes, U is the potential difference in volts, and R is a constant, measured in ohms, called the resistance.