View source for Emu system

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The '''emu system''' was a system of units for measuring electrical and magnetic quantities based on the [[CGS system|centimetre–gram–second (CGS) system]]. They were developed by the [[British Association for the Advancement of Science]] (B.A.) from 1862 to 1873, based on an original idea by [[Wilhelm Weber|Weber]], and rendered obsolete by the introduction of electrical and magnetic units into the [[International System of Units]] (SI) in 1948.

The emu system was usually treated as a non-rationalized three-quantity system in which [[electric current]], for example, had the [[dimension]] ([[force]])<sup>½</sup>. The [[magnetic constant]] (known at the time as the "permeability of free space") was literally ignored: in modern terms, it was set as dimensionless and with a value of 1. For these reasons, the form of [[quantity equation]]s intended for use with the emu system is often different from that of the corresponding equations in the four-quantity rationalized [[International System of Quantities]].<ref>{{GreenBook2nd|pages=117–23}}.</ref>

==Units==
{| class="wikitable"
|-
!
! Name
! SI equivalent
|-
| emu of [[electric current]]
| abampere<br/>biot
| 10 [[Ampere|A]]
|-
|}

==Notes and references==
===Notes===
{{reflist|group=Note}}

===References===
{{reflist}}

==External links==
*[http://www.sizes.com/units/sys_cgs_em.htm Sizes.com]

[[Category:Electrical units|*emu]]
[[Category:Magnetic units|*emu]]