资源描述：
《物理知识点积累》由会员上传分享，免费在线阅读，更多相关内容在工程资料-天天文库。
1、物理知识点积累ElementaryknowledgeofthefirstthreephysicalbooksOne,thecircuitknowledgeinductionInnaturethereareonlytwokindsofcharge,positiveandnegative.Positivecharge:thechargeontheglassbarthatwe'verubbedagainstthesilkiscalledapositivechargeNegativecharge:thechargetha
2、twebringtotherubberbarthatwe'verubbedwithfuriscalledanegativecharge・Thesamechargeandmutuallyexclusivechargesattracteachother3chargedbodyischaracteristicofsmallobjectsattractlight,soifthetwosmallballrepeleachother,thetwoballswillbringthesamecharge,attracteacho
3、ther,ifthetwoballsmaybetwogoalswithacharge,mayalsobeacharged,anotherballisnotcharged・Thelaboratoryusuallytestselectricalappliancestocheckiftheobjectischarged・Theprincipleofelectricalappliances:thesamechargerepeleachother・Staticapplication:electrostaticsprayin
4、g,staticflocking,electrostaticprecipitation,electrostaticcopying,etc・Electrostaticprotection:thetailofthetankerisoftendraggedbyanironchain,andthedownyprocessingworkshopistohumidifytheairintheworkshop,andthelightningrodisthelightningrod・Powersupply:adevicethat
5、providescontinuouscurrent(orvoltage).Thepowersupplyisconvertingotherformsofenergyintoelectricity・Forexample,drycellsconvertchemicalenergyintoelectricity・Ageneratorisconvertedbymechanicalenergyintoelectricity・Thesimplestcircuit:apowerswitchismadeupofelectrical
6、wiring,etc・Thereisaconditionforcontinuouscurrent:theremustbepowerandcircuitclosing・Aconductor:anobjectthatiseasilyconductiveiscalledaconductor・Forexample:metal,humanbody,earth,acid,alkali,saltsolution,etc・Insulator:anobjectthatisnoteasilyconductiveiscalledani
7、nsulator・Rubbet,glass,ceramic,plastic,oil,purewateretc.Thecircuithasthreestates:(1)access:thecircuitthatisconnectediscalledthepath;(2)thebrokencircuit:thebrokencircuitiscalledopenroad;(3)shortcircuit:thecircuitdirectlycormectedtothesourceofthepowersourceiscal
8、ledashortcircuit・Anelectriccurrentinashortcircuitistoolargetoburnthepowersupplyorcauseafire・Circuitdiagram:thesymboloftheelectricalcircuitiscalledacircuitdiagram・Inseries:thecircuitthatco
