Difference between revisions of "Volt"

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The '''volt''' (symbol: '''V''') is the [[SI unit]] of [[electric potential difference]] and [[electromotive force]]. It is named after the Italian physicist [[Alessandro Volta]] (1745–1827).
 
The '''volt''' (symbol: '''V''') is the [[SI unit]] of [[electric potential difference]] and [[electromotive force]]. It is named after the Italian physicist [[Alessandro Volta]] (1745–1827).
  
A similar unit, used for practical measurements of potential difference, is the '''conventional volt''' (symbol: '''''V''<sub>90</sub>''').<ref group="note">''V''<sub>90</sub> is considered to be a [[physical constant]], hence the use of italics for the symbol.</ref> The 2006 CODATA recommended value for ''V''<sub>90</sub> is:
+
A similar unit, used for practical measurements of potential difference, is the '''conventional volt''' (symbol: '''''V''<sub>90</sub>''').<ref group="note">''V''<sub>90</sub> is considered to be a [[physical constant]], hence the use of italics for the symbol.</ref> The 2006 CODATA recommended value for ''V''<sub>90</sub> is:<ref>{{CODATA 2006}}.</ref>
:''V''<sub>90</sub> = (''K''{{sub|J–90}}/''K''{{sub|J}})&nbsp;V = [1 + 1.9(2.5){{e|−8}}]&nbsp;V
+
:''V''<sub>90</sub> = (''K''<sub>J–90</sub>/''K''<sub>J</sub>)&nbsp;V = [1 + 1.9(2.5){{e|−8}}]&nbsp;V
 
The '''international volt''' (symbol: '''V<sub>int</sub>''') is now obsolete.
 
The '''international volt''' (symbol: '''V<sub>int</sub>''') is now obsolete.
  

Revision as of 21:50, 30 July 2010

The volt (symbol: V) is the SI unit of electric potential difference and electromotive force. It is named after the Italian physicist Alessandro Volta (1745–1827).

A similar unit, used for practical measurements of potential difference, is the conventional volt (symbol: V90).[note 1] The 2006 CODATA recommended value for V90 is:[1]

V90 = (KJ–90/KJ) V = [1 + 1.9(2.5) × 10−8] V

The international volt (symbol: Vint) is now obsolete.

Definition

The volt is defined as the potential difference between two points on a conductor when the current flowing is one ampere and the power dissipated is one watt.[2]

Conventional volt

Realization

History

Notes and references

Notes

  1. V90 is considered to be a physical constant, hence the use of italics for the symbol.

References

  1. Mohr, Peter J.; Taylor, Barry N.; Newell, David B. CODATA Recommended Values of the Fundamental Physical Constants: 2006. Rev. Mod. Phys. 2008, 80 (2), 633–730. doi:10.1103/RevModPhys.80.633, <http://physics.nist.gov/cuu/Constants/codata.pdf>.
  2. CIPM (1946), Resolution 2.

External links

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