Editing Electric current (section)

==Ohm's law==
{{Main|Ohm's law}}

Ohm's law states that the current through a conductor between two points is directly [[Proportionality (mathematics)|proportional]] to the [[potential difference]] across the two points.  Introducing the constant of proportionality, the [[Electrical resistance|resistance]],<ref>{{cite book
 | title = Automotive ignition systems
 |author1=Consoliver, Earl L. |author2=Mitchell, Grover I.
 | publisher = McGraw-Hill
 | year = 1920
 | page = [https://archive.org/details/automotiveignit03divigoog/page/n17 4]
 | url = https://archive.org/details/automotiveignit03divigoog
 | quote = ohm's law current proportional voltage resistance.
 }}</ref> one arrives at the usual mathematical equation that describes this relationship:<ref name=Millikan>{{cite book
 | title = Elements of Electricity
 | author = [[Robert A. Millikan]] and E. S. Bishop
 | publisher = American Technical Society
 | year = 1917
 | page = [https://archive.org/details/elementselectri00bishgoog/page/n67 54]
 | url = https://archive.org/details/elementselectri00bishgoog
 | quote = Ohm's law  current directly proportional.
 }}</ref>
<math display=block>I = \frac{V}{R},</math>

where ''I'' is the current through the conductor in units of [[ampere]]s, ''V'' is the potential difference measured ''across'' the conductor in units of [[volt]]s,  and ''R'' is the [[electrical resistance|resistance]] of the conductor in units of [[ohm]]s.  More specifically, Ohm's law states that the ''R'' in this relation is constant, independent of the current.<ref>{{cite book
 | title = Electrical papers
 | volume = 1
 | author = Oliver Heaviside
 | publisher = Macmillan and Co
 | year = 1894
 | page = 283
 | url = https://books.google.com/books?id=lKV-AAAAMAAJ&q=ohm's%20law%20constant%20ratio&pg=PA284
 | isbn = 978-0-8218-2840-3
 }}</ref>