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A conductorIn science and engineering, conductors are materials that contain movable charges of electricity. When an electric potential difference is impressed across separate points on a conductor, an electric current between those points appears in accordance with such as a metal has high conductivity, and an insulatorInsulators are materials which prevent the flow of heat (thermal insulators) or electrical current (electrical insulators). The opposite of electrical insulators are conductors and semiconductors, which permit the flow of current (Note: a semiconductor is like glass or a vacuum has low conductivity. A semiconductorA semiconductor is a material that is an insulator at very low temperature, but which has a sizable electrical conductivity at room temperature. The distinction between a semiconductor and an insulator is not very well-defined, but roughly, a semiconducto has a conductivity that varies widely under different conditions, such as exposure of the material to electric fields or certain frequencies of light.
Electrical conductivity is the reciprocalIn mathematics, the reciprocal or multiplicative inverse of a number x is the number which, when multiplied by x, yields 1. Zero does not have a reciprocal. Every complex number except zero has a reciprocal that is a complex number. If it is real then so of electrical resistivityElectrical resistivity (also known as specific electrical resistance is a measure indicating how strongly a material opposes the flow of electric current. A low resistivity indicates a material that readily allows the movement of electrons. The SI unit fo (1/[Ω·m]).
| SI electricity units [ }|action=edit}} Edit }] | |||
|---|---|---|---|
| SI Base unit | |||
| Name | Symbol | Quantity | Notes |
| ampere | A | Current | |
| SI Derived units | |||
| Name | Symbol | Quantity | Notes |
| volt | V | Potential difference | |
| ohm | Ω | Resistance, Impedance, Reactance | |
| farad | F | Capacitance | |
| henry | H | Inductance | |
| siemens | S | Conductance, Admittance, Susceptance | =Ω−1 |
| coulomb | C | Electric charge | |
| ohm · metre | Ω · m | Resistivity | |
| siemens per metre | S / m | Conductivity | |
| henry per metre | H /m | Permeability | μ |
| farad per metre | F / m | Permittivity | ε |
| reciprocal farad | F−1 | Elastance | =F−1 |