short definition: ability to conduct heat or electricity
scalar or tensor quantity the product of which by the electric field strength in a medium is equal to the electric current density
see also International Annealed Conductivity Standard (IACS); resistivity; electrical conductivity; thermal conductivity; ampacity; current rating; Ohm's Law
note: An equivalent expression to Ohm's Law is that current density is the product of conductivity and the electric field (volt/meter in an anisotropic medium). Conductivity is defined as the reciprocal of electrical resistivity. It is a material property expressed in siemens/m (S/m). Copper's conductivity of 58 S/m at 20 degrees sets the standard of 100% IACS.
standard IEC 60028