通常情況下，電動機是用磁鐵把電(dian)(dian)能轉(zhuan)(zhuan)換成機(ji)械能。永(yong)磁(ci)(ci)體(ti)被放(fang)置在(zai)(zai)導(dao)電(dian)(dian)物(wu)質中(zhong)，來自磁(ci)(ci)體(ti)的磁(ci)(ci)場帶動(dong)(dong)(dong)另一件設備，使電(dian)(dian)機(ji)快速旋(xuan)轉(zhuan)(zhuan)。永(yong)磁(ci)(ci)體(ti)也可以(yi)(yi)起(qi)到相(xiang)反的作用(yong)，將(jiang)機(ji)械力(li)(li)轉(zhuan)(zhuan)化為電(dian)(dian)力(li)(li)。將(jiang)兩塊永(yong)磁(ci)(ci)體(ti)相(xiang)對放(fang)置會(hui)產生斥力(li)(li)，使渦輪(lun)旋(xuan)轉(zhuan)(zhuan)，渦輪(lun)就會(hui)轉(zhuan)(zhuan)動(dong)(dong)(dong)一個叫做電(dian)(dian)樞的旋(xuan)轉(zhuan)(zhuan)線圈，從而產生電(dian)(dian)能。自上(shang)世紀90年代釹磁(ci)(ci)鐵變得更(geng)便宜以(yi)(yi)來，釹磁(ci)(ci)鐵在(zai)(zai)許多高科技應用(yong)中(zhong)取代了早期的鋁鎳鈷和鐵氧(yang)體(ti)永(yong)磁(ci)(ci)。常見用(yong)途包括(kuo)計算機(ji)硬盤(pan)驅動(dong)(dong)(dong)器、風力(li)(li)渦輪(lun)機(ji)、揚聲器/耳機(ji)、MRI掃描(miao)儀(yi)、無繩工具電(dian)(dian)機(ji)；以(yi)(yi)及(ji)燃(ran)油汽車(che)(che)、混合動(dong)(dong)(dong)力(li)(li)和電(dian)(dian)動(dong)(dong)(dong)汽車(che)(che)的各種電(dian)(dian)機(ji)，甚至各種工業電(dian)(dian)機(ji)。