Ohm's Law

Ohm's Law describes the relationship between current ($I$), voltage ($V$), and resistance ($R$), so that current, which is the flow of electricity, is defined as:

$I = V/R$

Given the values for any two variables, we solve for the third, so that voltage, electrical potential energy, is defined as:

$V = IR$

And resistance, which impedes the flow of electricity, is:

$R = V/I$

Conductance ($G$), which is the ability for a material to conduct electricity is defined as the inverse of resistance, and can therefore calculated by Ohm's Law as:

$G = I/V$

Video: Circuits and Ohm's Law

History

Ohm's Law is named after Georg Simon Ohm, who first derived the relationships now known as Ohm's Law.