InDCcircuits,capacitorsareequivalenttoopencircuits.Capacitorsareoneofthemostcommonlyusedelectroniccomponentstostorecharge.However,inACcircuits,thedirectionofthecurrentchangeswithtime.Thecharginganddischargingprocessofcapacitorsistime-dependent,andatthistime,avaryingelectricfieldisformedbetweentheplates,andthiselectricfieldisafunctionofthechangewithtime.Infact,thecurrentpassesbetweencapacitorsintheformofanelectricfield.Thefunctionofcapacitors:coupling:thecapacitorsusedincouplingcircuitsarecalledcouplingcapacitors.Theyarewidelyusedinresistiveandcapacitivecoupledamplifiersandothercapacitivecouplingcircuitstoactasanalternatingcurrentbetweendirectcurrentanddirectcurrent[2].Filtering:capacitorsusedinfiltercircuitsarecalledfiltercapacitors,whichareusedinpowersupplyfilteringandvariousfiltercircuits.Thefiltercapacitorsremovesignalsinacertainfrequencybandfromthetotalsignal[2].)