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| [[Image:Inductor.jpg|thumb|150px|An [[inductor]] composed of a [[wire]] wound around a [[magnetic core]] used to confine and guide the induced [[magnetic field]].]]
| | I'm Esperanza and I live in Dayton. <br>I'm interested in Social Service, Writing and Chinese art. I like to travel and watching Psych.<br><br>Here is my web-site; [https://www.ezcamsites.com/ cam affiliate program] |
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| In [[physics]], and [[electronics]], the '''henry''' (symbol '''H''') is the [[SI derived unit]] of [[inductance]].<ref>{{cite web | title=How Many? A Dictionary of Units of Measurement | last=Rowlett | first = Russ | url = http://www.unc.edu/~rowlett/units/dictH.html | publisher = [[University of North Carolina at Chapel Hill]]}}</ref> It is named after [[Joseph Henry]] (1797–1878), the American scientist who discovered electromagnetic induction independently of and at about the same time as [[Michael Faraday]] (1791–1867) in England.<ref>{{cite web | title = A Princeton Companion | url = http://etcweb.princeton.edu/CampusWWW/Companion/henry_joseph.html | author = Herbert S. Bailey, Jr.}}</ref> The [[magnetic permeability]] of a vacuum is 4π×10<sup>−7</sup> H/m (henry per meter).
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| The [[National Institute of Standards and Technology]] provides guidance for American users of SI to write the plural as henries.<ref name=Taylor>{{Cite journal|author=Ambler Thompson & Barry N. Taylor|year=2008|url=http://physics.nist.gov/cuu/pdf/sp811.pdf|title=NIST Special Publication 811: Guide for the Use of the International System of Units (SI)|publisher=National Institute of Standards and Technology|accessdate=2013-03-21}}
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| </ref>{{rp|31}} | |
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| == Definition ==
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| If the rate of change of [[Current (electricity)|current]] in a circuit is one [[ampere]] per [[second]] and the resulting [[electromotive force]] is one [[volt]], then the [[inductance]] of the circuit is one henry. Other equivalent combinations of SI units are as follows:<ref>{{cite web | title = Essentials of the SI: Base & derived units | work = The NIST Reference on Constants, Units and Uncertainty | url = http://physics.nist.gov/cuu/Units/units.html | publisher = [[National Institute of Standards and Technology]]}}</ref>
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| :<math>\mbox{H}
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| = \dfrac{\mbox{m}^2 \cdot \mbox{kg}}{\mbox{C}^2}
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| = \dfrac{\mbox{m}^2 \cdot \mbox{kg}}{\mbox{s}^{2} \cdot \mbox{A}^2}
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| = \dfrac{\mbox{J}}{\mbox{A}^2}
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| = \dfrac{\mbox{Wb}}{\mbox{A}}
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| = \dfrac{\mbox{V} \cdot \mbox{s}}{\mbox{A}}
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| = \dfrac{\mbox{s}^2}{\mbox{F}}
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| = \Omega \cdot \mbox{s}
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| </math>
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| where
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| A = [[ampere]],
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| <br>C = [[coulomb]],
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| <br>F = [[farad]],
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| <br>J = [[joule]],
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| <br>kg = [[kilogram]],
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| <br>m = [[meter]],
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| <br>s = [[second]],
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| <br>Wb = [[Weber (unit)|weber]],
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| <br>V = [[volt]],
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| <br>Ω = [[ohm]].
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| == Notes and references ==
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| {{Reflist|2}}
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| == See also ==
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| * [[Electrical impedance|Impedance]]
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| * [[Inductor]]
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| * [[Weber (unit)]]
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| {{SI units}}
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| [[Category:SI derived units]]
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| [[Category:Units of electrical inductance]]
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I'm Esperanza and I live in Dayton.
I'm interested in Social Service, Writing and Chinese art. I like to travel and watching Psych.
Here is my web-site; cam affiliate program