Editing Electric current (section)

==Resistive heating==
{{Main|Joule heating}}
Joule heating, also known as ''ohmic heating'' and ''resistive heating'', is the process of [[power dissipation]]<ref name="JaffeTaylor">{{cite book |last1=Jaffe |first1=Robert L. |last2=Taylor |first2=Washington |title=The physics of energy |date=2018 |publisher=Cambridge University Press }}</ref>{{rp|36}} by which the passage of an electric current through a [[conductor (material)|conductor]] increases the [[internal energy]] of the conductor,<ref name="SerwayJewett2004">{{cite book|last=Serway|first=Raymond A.|url=https://archive.org/details/physicssciengv2p00serw|title=Physics for Scientists and Engineers|author2=Jewett, John W.|publisher=Thomson Brooks/Cole|year=2004|isbn=0-534-40842-7|edition=6th|url-access=registration}}</ref>{{rp|846}} converting [[thermodynamic work]] into [[heat]].<ref name="SerwayJewett2004"/>{{rp|846, fn. 5}} The phenomenon was first studied by [[James Prescott Joule]] in 1841. Joule immersed a length of wire in a fixed [[mass]] of [[water]] and measured the [[temperature]] rise due to a known current through the wire for a 30 [[minute]] period. By varying the current and the length of the wire he deduced that the heat produced was [[proportionality (mathematics)|proportional]] to the [[square (algebra)|square]] of the current multiplied by the [[electrical resistance]] of the wire.

<math display=block>P \propto I^2 R. </math>

This relationship is known as [[Joule's first law|Joule's Law]].<ref name="JaffeTaylor"/>{{rp|36}} The [[SI unit]] of [[energy]] was subsequently named the [[joule]] and given the symbol ''J''.<ref name="SI"/>{{rp|20}} The commonly known SI unit of power, the [[watt]] (symbol: W), is equivalent to one joule per second.<ref name="SI"/>{{rp|20}}