電阻(zu)(zu)器是限制電流(liu)的元件,通常簡稱為電阻(zu)(zu),是一種最常用(yong)的電子元件,普遍應用(yong)在各類電子電路中。不但金(jin)屬導體(ti)有(you)電阻(zu)(zu),其他(ta)物體(ti)也有(you)電阻(zu)(zu)。
簡單(dan)來(lai)說(shuo),電(dian)(dian)(dian)(dian)阻就是指電(dian)(dian)(dian)(dian)流(liu)在電(dian)(dian)(dian)(dian)路中所遇到的阻力,或(huo)者說(shuo)是指物體對電(dian)(dian)(dian)(dian)流(liu)的阻礙(ai)才能。電(dian)(dian)(dian)(dian)阻越(yue)大(da),電(dian)(dian)(dian)(dian)流(liu)所遭到的阻力就越(yue)大(da),因而電(dian)(dian)(dian)(dian)流(liu)就越(yue)小(xiao)。反之,電(dian)(dian)(dian)(dian)阻越(yue)小(xiao),電(dian)(dian)(dian)(dian)流(liu)所遭到的阻力就越(yue)小(xiao),因而電(dian)(dian)(dian)(dian)流(liu)就越(yue)大(da)。
電阻的(de)(de)符號是“R”。電阻的(de)(de)單(dan)位為歐姆,簡稱歐,用(yong)(yong)字母(mu)“Ω”表(biao)示(shi)。常用(yong)(yong)的(de)(de)電阻單(dan)位還(huan)有千歐姆(KΩ),兆歐姆(MΩ)。