電阻器是限制電流的元件,通常簡稱為(wei)電阻,是一種(zhong)最常用的電子(zi)元件,普(pu)遍應(ying)用在各(ge)類(lei)電子(zi)電路中。不但金(jin)屬導體有電阻,其他物體也有電阻。
簡單來說,電(dian)(dian)(dian)阻(zu)就是(shi)指電(dian)(dian)(dian)流(liu)在(zai)電(dian)(dian)(dian)路中(zhong)所(suo)遇到的(de)阻(zu)力,或者說是(shi)指物體對(dui)電(dian)(dian)(dian)流(liu)的(de)阻(zu)礙才能。電(dian)(dian)(dian)阻(zu)越(yue)大(da),電(dian)(dian)(dian)流(liu)所(suo)遭到的(de)阻(zu)力就越(yue)大(da),因而電(dian)(dian)(dian)流(liu)就越(yue)小。反(fan)之,電(dian)(dian)(dian)阻(zu)越(yue)小,電(dian)(dian)(dian)流(liu)所(suo)遭到的(de)阻(zu)力就越(yue)小,因而電(dian)(dian)(dian)流(liu)就越(yue)大(da)。
電(dian)(dian)阻的符號(hao)是(shi)“R”。電(dian)(dian)阻的單位(wei)為歐姆(mu),簡稱歐,用(yong)字母“Ω”表示。常用(yong)的電(dian)(dian)阻單位(wei)還有千歐姆(mu)(KΩ),兆歐姆(mu)(MΩ)。