Resistance

Resistance is the opposition a conductor, cable, component or load presents to electric current, measured in Ω (ohms). NIST (National Institute of Standards and Technology) gives the SI (International System of Units) unit of electric resistance as the ohm, with 1 Ω equal to 1 V/A (volt per ampere). In home energy documents, resistance may appear in Ohm's law calculations, cable or conductor data, insulation resistance results, earth fault loop impedance context and equipment fault notes.