Electrical conductivity or
specific conductance is a measure of a material's ability to
conduct an
electric current. When an
electrical potential difference is placed across a conductor, its movable charges flow, giving rise to an electric current. The conductivity s is defined as the ratio of the
current density J to the
electric field strength
EIt is also possible to have materials in which the conductivity is anisotropic, in which case s is a 3×3 matrix (or more technically a rank-2 tensor) which is generally symmetric.
Conductivity is the reciprocal (inverse) of electrical resistivity, ?, and has the SI units of siemens per metre (S·m-1)
Electrical conductivity is commonly represented by the Greek letter s, but ? (esp. in electrical engineering science) or ? are also occasionally used.
