Electrical resistivity and conductivity 1 Ω⋅m. Electrical conductivity or specific conductance is the reciprocal of electrical resistivity, and measures a material's ability to conduct an electric current. It is commonly represented by the Greek letter σ (sigma), but κ (kappa) (especially in electrical engineering) or γ (gamma) are also occasionally used. Its SI unit is siemens per metre (S/m). In an ideal case, cross-section and physical composition of the examined material are uniform across the sample, and the electric field and current density are both parallel and constant everywhere. Many resistors and conductors do in fact have a uniform cross section with a uniform
Edmundson Electrical Electrical Distributors, which in 2010 was the fifth largest private company by revenue ($3.4 billion in 2009, $3.9 billion in 2008). Through a number of companies, the Colburn family own a global network of manufacturers, distributors and general purpose retail outlets. Whilst Edmunson Electrical primarily serves the United Kingdom and Ireland, the parent organisation, Marlowe Holdings Investments has an 80.1% stake in the Mainland Europe based preformed plastics distributor, Vink Holdings. Edmundson Electrical Edmundson Electrical Ltd is a privately held electrical distribution company headquartered in Knutsford, Cheshire, incorporated in 1991. It is the largest electrical distributor in the United Kingdom