What is Capacitor?
{{refimprove|date=December 2011}} [[Image:Photo-SMDcapacitors.jpg|thumb|250px|Modern capacitors, by a cm ruler]] [[File:Condensator symbol.svg|thumb|right|Capacitor symbol]] A '''capacitor''' (also called '''condenser''', which is the older term) is an [[Electronics|electronic]] device that stores electric energy. It is similar to a [[battery]], but can be smaller, lightweight and a capacitor charges or discharges much quicker. Capacitors are used in many electronic devices today, and can be made out of many different types of material. The [[Leyden jar]] was one of the first capacitors invented. Capacitors are usually made with two metal plates that are on top of each other and near each other, but that do not actually touch. When powered, they allow energy to be stored inside an electrical field. Because the plates need a lot of area to store even a small amount of [[electric charge|charge]], the plates are usually rolled up into some other shape, such as a [[cylinder]]. Sometimes, other shapes of capacitors are used for special purposes. A capacitor-like effect can also result just from two [[Electrical conductor|conductors]] being close to each other, whether you want it to exist or not.<ref>{{cite book|last=Ulaby|first=Fawwaz T.|title=Fundamentals of Applied Electromagnetics|url=https://archive.org/details/fundamentalsofap0000ulab_o5j2|edition=1999|publisher=Prentice-Hall|location=Upper Saddle River, New Jersey|year=1999|isbn=0-13-011554-1|page=[https://archive.org/details/fundamentalsofap0000ulab_o5j2/page/168 168]}}</ref> The type of capacitor used depends on the application. Capacitors come in many sizes. They can be as small as an [[ant]] or as large as a [[dustbin]]. A few capacitors are adjustable. All capacitors have two connections, or leads. Most kinds of capacitors can be replaced easily by someone who has basic skills in electronics. However, one of the more powerful types - the electrolytic capacitor - must be used the correct way, or they can explode violently. While capacitors can stor