Thursday, September 3, 2009

Electrical Conductivity

Electrical conductivity is the capacity of matter to conduct an electric current, indicating the ease with which electrical current flows through it. When an electrical potential difference is placed across a conductor, its movable charges flow, giving rise to an electric current. The conductivity σ is defined as the ratio of the current density J to the electric field strength E.

A conductor such as a metal has high electrical conductivity and a low resistivity. An insulator like glass or plastic has low conductivity and a high resistivity. Silver, copper, gold, and aluminum have the highest electrical conductivity.