What unit measures electrical resistance?

The unit that measures electrical resistance is the ohm. The ohm is defined as the resistance that allows one ampere of current to flow when one volt of electrical potential is applied. This relationship is grounded in Ohm's Law, which states that voltage equals current multiplied by resistance (V = I x R). Understanding this unit is essential in electrical engineering and electronics because it helps quantify how much a material opposes the flow of electric current.

Other units, such as the volt, measure electrical potential; the watt measures power (which is the rate of doing work or transferring energy); and the ampere measures current, which is the flow of electric charge. Thus, each of these units serves a different purpose in the context of electricity, but the ohm is the standard unit used solely for resistance.