Engineering

Cooler transformers could help electric grid

Most people do not give the U.S. electric grid a second thought—we flip a switch, and the lights come on. Behind the scenes are thousands of power plants and utilities linked by millions of miles of transmission lines. ...

Electrical conductivity

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 σ is defined as the ratio of the current density to the electric field strength :

It is also possible to have materials in which the conductivity is anisotropic, in which case σ is a 3×3 matrix (or more technically a rank-2 tensor) which is generally symmetric.

Conductivity is the reciprocal (inverse) of electrical resistivity, ρ, and has the SI units of siemens per metre (S·m-1):

Electrical conductivity is commonly represented by the Greek letter σ, but κ (esp. in electrical engineering science) or γ are also occasionally used.

An EC meter is normally used to measure conductivity in a solution.

This text uses material from Wikipedia, licensed under CC BY-SA