Electrical conductivity
From Simple English Wikipedia, the free encyclopedia
Electrical conductivity is a measure of how well a material accommodates the transport of electric charge. Its SI derived unit is the siemens per metre, (A2s3m-3kg-1) (named after Werner von Siemens) or, more simply, Sm-1. It is the ratio of the current density to the electric field strength or, in more practical terms, is equivalent to the electrical conductance measured between opposite faces of a 1-metre cube of the material under test.
- As symbol for electrical conductivity we find κ (kappa), but also σ (sigma) or γ (gamma).
Elecrical conductance is an electrical phenomenon where a material contains movable particles with electric charge (such as electrons), which can carry electricity. When a difference of electrical potential is placed across a conductor, its movable charges flow, and an electric current appears.
A conductor such as a metal has high conductivity, and an insulator like glass or a vacuum has low conductivity. A semiconductor has a conductivity that varies widely under different conditions.
Electrical conductivity is the reciprocal (or inverse) of electrical resistivity.