Molecular vibration

Ohm's law states that, in an electrical circuit, the current passing through a conductor, from one terminal point to another, is directly proportional to the potential difference (i.e. voltage drop or voltage) across the two terminal points and inversely proportional to the resistance of the conductor between the two terminal points. The SI unit of current is the ampere; that of potential difference is the volt; and that of resistance is the ohm, equal to one volt per ampere.

In mathematical terms, this is written as:

$I={\frac {V}{R}}$,

where I is the current, V is the potential difference, and R is a constant called the resistance.