通常情況下，電動機是用磁鐵把(ba)電(dian)(dian)(dian)(dian)能轉換成(cheng)機(ji)(ji)械(xie)(xie)能。永(yong)磁(ci)(ci)體(ti)被放置(zhi)(zhi)在導電(dian)(dian)(dian)(dian)物質(zhi)中(zhong)，來自磁(ci)(ci)體(ti)的(de)(de)磁(ci)(ci)場帶動(dong)(dong)另一(yi)件設備，使電(dian)(dian)(dian)(dian)機(ji)(ji)快速旋(xuan)(xuan)轉。永(yong)磁(ci)(ci)體(ti)也可(ke)以起到相反(fan)的(de)(de)作(zuo)用(yong)，將機(ji)(ji)械(xie)(xie)力(li)(li)轉化為電(dian)(dian)(dian)(dian)力(li)(li)。將兩(liang)塊永(yong)磁(ci)(ci)體(ti)相對放置(zhi)(zhi)會(hui)產生斥(chi)力(li)(li)，使渦(wo)輪旋(xuan)(xuan)轉，渦(wo)輪就會(hui)轉動(dong)(dong)一(yi)個叫做電(dian)(dian)(dian)(dian)樞(shu)的(de)(de)旋(xuan)(xuan)轉線圈，從而產生電(dian)(dian)(dian)(dian)能。自上世紀90年代釹磁(ci)(ci)鐵變(bian)得更便宜以來，釹磁(ci)(ci)鐵在許(xu)多高科技應用(yong)中(zhong)取代了早期的(de)(de)鋁鎳鈷和鐵氧(yang)體(ti)永(yong)磁(ci)(ci)。常(chang)見(jian)用(yong)途(tu)包(bao)括計(ji)算機(ji)(ji)硬盤驅動(dong)(dong)器(qi)、風力(li)(li)渦(wo)輪機(ji)(ji)、揚聲器(qi)/耳機(ji)(ji)、MRI掃描(miao)儀、無繩工具電(dian)(dian)(dian)(dian)機(ji)(ji)；以及燃油汽(qi)車、混合動(dong)(dong)力(li)(li)和電(dian)(dian)(dian)(dian)動(dong)(dong)汽(qi)車的(de)(de)各(ge)種(zhong)電(dian)(dian)(dian)(dian)機(ji)(ji)，甚至各(ge)種(zhong)工業(ye)電(dian)(dian)(dian)(dian)機(ji)(ji)。