Open main menu
Home
Random
Recent changes
Special pages
Community portal
Preferences
About Wikipedia
Disclaimers
Incubator escapee wiki
Search
User menu
Talk
Dark mode
Contributions
Create account
Log in
Editing
Admittance
(section)
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
{{Short description|Ease of electrical current flow}} {{about|electrical engineering}} In [[electrical engineering]], '''admittance''' is a measure of how easily a circuit or device will allow a current to flow. It is defined as the [[multiplicative inverse|reciprocal]] of [[Electrical impedance|impedance]], analogous to how [[Electrical resistance and conductance|conductance and resistance]] are defined. The [[SI]] unit of admittance is the [[siemens (unit)|siemens]] (symbol S); the older, synonymous unit is [[mho]], and its symbol is β§ (an upside-down uppercase omega Ξ©). [[Oliver Heaviside]] coined the term ''admittance'' in December 1887.<ref>{{Cite journal|doi=10.1103/PhysRevB.68.155115|title=Immittance matching for multidimensional open-system photonic crystals|year=2003|last1=Ushida|first1=Jun|last2=Tokushima|first2=Masatoshi|last3=Shirane|first3=Masayuki|last4=Gomyo|first4=Akiko|last5=Yamada|first5=Hirohito|journal=Physical Review B|volume=68|issue=15|page=155115|arxiv = cond-mat/0306260 |bibcode = 2003PhRvB..68o5115U |s2cid=119500762}}</ref> Heaviside used {{mvar|Y}} to represent the magnitude of admittance, but it quickly became the conventional symbol for admittance itself through the publications of [[Charles Proteus Steinmetz]]. Heaviside probably chose {{mvar|Y}} simply because it is next to {{mvar|Z}} in the alphabet, the conventional symbol for impedance.<ref>Ronald R. Kline, ''Steinmetz: Engineer and Socialist'', p. 88, Johns Hopkins University Press, 1992 {{ISBN|0801842980}}.</ref> Admittance {{mvar|Y}}, measured in [[Siemens (unit)|siemens]], is defined as the inverse of [[Electrical impedance|impedance]] {{mvar|Z}}, measured in [[Ohm (unit)|ohms]]: <math display="block">Y \equiv \frac{1}{Z}</math> [[electrical resistance|Resistance]] is a measure of the opposition of a circuit to the flow of a steady current, while impedance takes into account not only the resistance but also dynamic effects (known as [[Electrical reactance|reactance]]). Likewise, admittance is not only a measure of the ease with which a steady current can flow, but also the dynamic effects of the material's susceptance to polarization: <math display="block">Y = G + j B \,,</math> where * {{mvar|Y}} is the admittance (siemens); * {{mvar|G}} is the [[Electrical conductance|conductance]] (siemens); * {{mvar|B}} is the [[susceptance]] (siemens); and * {{math|1= ''j''{{isup|2}} = β1}}, the [[imaginary unit]]. The dynamic effects of the material's susceptance relate to the [[universal dielectric response]], the power law scaling of a system's admittance with frequency under alternating current conditions.
Edit summary
(Briefly describe your changes)
By publishing changes, you agree to the
Terms of Use
, and you irrevocably agree to release your contribution under the
CC BY-SA 4.0 License
and the
GFDL
. You agree that a hyperlink or URL is sufficient attribution under the Creative Commons license.
Cancel
Editing help
(opens in new window)