| • Science | • People | • Locations | • Timeline |
The volt is defined as the potential difference across a conductor when a current of one ampere dissipates one watt of power. Hence, it is has the base SI representation m2 · kg · s-3 · A-1, which can be equally represented as one jouleThe joule (symbol J also called newton metre or coulomb volt is the SI unit of energy and work. The unit is pronounced to rhyme with "tool", and is named in honour of the physicist James Prescott Joule (1818-1889). 1 joule 1 N · 1 m 1 newton · 1 metre 1 k of energyThis article is about the scientific concept. Energy use by humans is discussed in other articles''. Energy generally and qualitatively speaking, is the property (or the quantity of the property) of doing things or supplying power. The expressions energy per coulombThe coulomb symbol C, is the SI unit of electric charge, and is defined in terms of the ampere: 1 coulomb is the amount of electric charge carried by a current of 1 ampere flowing for 1 second. It is also about 6. 241506×1018 times the charge of an electr of charge, J/C.
The volt is since 1990 maintained internationally using the Josephson effectThe Josephson Effect is named after British Physicist Brian David Josephson who predicted its existence in 1962. We see the Josephson Effect through a flow of electric current as electron pairs, called Cooper Pairs, between two superconducting materials t, where a conventional value is used for the Josephson constant, fixed by the 18th CGPM as
K{J-90} = 0.4835979 GHz/µV.
| 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 |