電(dian)阻器是限制電(dian)流(liu)的元(yuan)件,通常簡(jian)稱為(wei)電(dian)阻,是一種(zhong)最(zui)常用(yong)的電(dian)子元(yuan)件,普遍應用(yong)在各類電(dian)子電(dian)路中。不但金屬導體有電(dian)阻,其(qi)他物體也有電(dian)阻。
簡單來說,電(dian)(dian)(dian)阻就(jiu)是指電(dian)(dian)(dian)流(liu)在(zai)電(dian)(dian)(dian)路(lu)中所(suo)遇到的(de)阻力(li),或(huo)者說是指物體對電(dian)(dian)(dian)流(liu)的(de)阻礙才能。電(dian)(dian)(dian)阻越(yue)(yue)大(da),電(dian)(dian)(dian)流(liu)所(suo)遭(zao)到的(de)阻力(li)就(jiu)越(yue)(yue)大(da),因(yin)(yin)而(er)電(dian)(dian)(dian)流(liu)就(jiu)越(yue)(yue)小。反之(zhi),電(dian)(dian)(dian)阻越(yue)(yue)小,電(dian)(dian)(dian)流(liu)所(suo)遭(zao)到的(de)阻力(li)就(jiu)越(yue)(yue)小,因(yin)(yin)而(er)電(dian)(dian)(dian)流(liu)就(jiu)越(yue)(yue)大(da)。
電阻的(de)(de)符號(hao)是“R”。電阻的(de)(de)單(dan)位(wei)為歐姆(mu),簡稱歐,用字母“Ω”表(biao)示(shi)。常用的(de)(de)電阻單(dan)位(wei)還有千歐姆(mu)(KΩ),兆歐姆(mu)(MΩ)。