Capacitance: Difference between revisions
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[[File:capacitor4.png|400px|framed|right|Figure 1. Drawing of a capacitor with the capacitance, 400 microfarads, marked on the side.<ref>"Electrolytic Capacitor, Radial, 16x30 (Coloured)" Licensed under Public Domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Electrolytic_Capacitor,_Radial,_16x30_(Coloured).svg#/media/File:Electrolytic_Capacitor,_Radial,_16x30_(Coloured).svg</ref>]] | [[File:capacitor4.png|400px|framed|right|Figure 1. Drawing of a capacitor with the capacitance, 400 microfarads, marked on the side.<ref>"Electrolytic Capacitor, Radial, 16x30 (Coloured)" Licensed under Public Domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Electrolytic_Capacitor,_Radial,_16x30_(Coloured).svg#/media/File:Electrolytic_Capacitor,_Radial,_16x30_(Coloured).svg</ref>]] | ||
<onlyinclude>'''Capacitance''' is the ability of an object | <onlyinclude>'''Capacitance''' is the ability of an object (material in a particular geometry) to store an electric [[charge]]. Specifically, it is a measure of an isolated [[conductor]]'s ability to store charge at a given [[voltage difference]].</onlyinclude><ref name = A>P. Tipler and G. Mosca, "Electrostatic Energy and Capacitance," in ''Physics for Scientists and Engineers Volume 2,'' 5th ed. Freeman, ch. 24, pp. 752-755</ref> In this sense, an object's capacitance is the ratio between its charge at a particular voltage difference and that voltage difference. Functionally, this leads to capacitance also being a measure of how much [[energy]] a [[capacitor#Energy in a capacitor|capacitor can store]]. | ||
Often a capacitance is thought of as being the physical property of a [[capacitor]] that has two conducting plates close to each other. The capacitance is described mathematically as: | Often a capacitance is thought of as being the physical property of a [[capacitor]] that has two conducting plates close to each other. The capacitance is described mathematically as: | ||
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<center>< | <center><math> C = \frac{q}{V} </math></center> | ||
:::* < | :::* <math>C</math> is the capacitance, measured in farads | ||
:::* < | :::* <math>q</math> is the charge that is on the positive plate of the capacitor, measured in [[coulomb]]s | ||
:::* < | :::* <math>V</math> is the [[voltage]] of the conductor, measured in [[volt]]s | ||
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<center>< | <center><math>C = \frac{\varepsilon_{0} \varepsilon_{r} A} {d}</math></center> | ||
:::* < | :::* <math>C</math> is the capacitance, measured in [[farad]]s (F) | ||
:::* < | :::* <math>\varepsilon_{0}</math> is a constant called the [[permittivity of free space]] = 8.854188x10<sup>-12</sup> F/m <ref> A. D. McNaught and A. Wilkinson. (2012, September 8). ''Permmittivity of vacuum'' <nowiki>[Online]</nowiki>. Available: http://goldbook.iupac.org/P04508.html</ref> | ||
:::* < | :::* <math>\varepsilon_{r}</math> is the relative permittivity of the material between the plates | ||
:::* < | :::* <math>A</math> is the surface area of the plates of the capacitor, measured in square [[metre]]s (m<sup>2</sup>) | ||
:::* < | :::* <math>d</math> is the distance between the plates, measured in metres (m) | ||
<br /> | <br /> | ||
The equation shows that the capacitance is influenced by the dimensions of the capacitor. | The equation shows that the capacitance is influenced by the dimensions of the capacitor. | ||
==For Further Reading== | |||
*[[Capacitor]] | |||
*[[Conductor]] | |||
*[[Voltage difference]] | |||
*[[Coulomb]] | |||
*[[Voltage]] | |||
*Or explore a [[Special:Random|random page]] | |||
==References== | ==References== | ||
{{Reflist}} | {{Reflist}} | ||
[[Category:Uploaded]] | [[Category:Uploaded]] |
Latest revision as of 05:10, 31 January 2020
Capacitance is the ability of an object (material in a particular geometry) to store an electric charge. Specifically, it is a measure of an isolated conductor's ability to store charge at a given voltage difference.[2] In this sense, an object's capacitance is the ratio between its charge at a particular voltage difference and that voltage difference. Functionally, this leads to capacitance also being a measure of how much energy a capacitor can store.
Often a capacitance is thought of as being the physical property of a capacitor that has two conducting plates close to each other. The capacitance is described mathematically as:
Capacitance is measured in farads (F), with 1 farad representing 1 coulomb per volt. This means that if an isolated conductor had a capacitance of 1 farad and was charged with 1 coulomb, it would have a voltage of 1 volt on its surface. There is also an alternate way to determine the capacitance of a capacitor if its dimensions are known. If the area of the plates of the capacitor can be determined, the capacitance can be calculated from the expression:[3]
- farads (F) is the capacitance, measured in
- permittivity of free space = 8.854188x10-12 F/m [4] is a constant called the
- is the relative permittivity of the material between the plates
- metres (m2) is the surface area of the plates of the capacitor, measured in square
- is the distance between the plates, measured in metres (m)
The equation shows that the capacitance is influenced by the dimensions of the capacitor.
For Further Reading
- Capacitor
- Conductor
- Voltage difference
- Coulomb
- Voltage
- Or explore a random page
References
- ↑ "Electrolytic Capacitor, Radial, 16x30 (Coloured)" Licensed under Public Domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Electrolytic_Capacitor,_Radial,_16x30_(Coloured).svg#/media/File:Electrolytic_Capacitor,_Radial,_16x30_(Coloured).svg
- ↑ P. Tipler and G. Mosca, "Electrostatic Energy and Capacitance," in Physics for Scientists and Engineers Volume 2, 5th ed. Freeman, ch. 24, pp. 752-755
- ↑ R. Kotz and M. Carlen, "Principles and applications of electrochemical capacitors," Electrochim. Acta, vol. 45, no. 15-16, pp. 2483-2498, May 2000.
- ↑ A. D. McNaught and A. Wilkinson. (2012, September 8). Permmittivity of vacuum [Online]. Available: http://goldbook.iupac.org/P04508.html