通常情況下，電動機是用磁鐵把電(dian)(dian)能轉(zhuan)(zhuan)(zhuan)換成機(ji)(ji)(ji)械能。永(yong)(yong)磁(ci)(ci)(ci)體(ti)被放置在(zai)導電(dian)(dian)物質中(zhong)，來自磁(ci)(ci)(ci)體(ti)的磁(ci)(ci)(ci)場(chang)帶動(dong)另(ling)一(yi)件設備，使(shi)電(dian)(dian)機(ji)(ji)(ji)快速旋轉(zhuan)(zhuan)(zhuan)。永(yong)(yong)磁(ci)(ci)(ci)體(ti)也(ye)可以(yi)起(qi)到相反的作用(yong)，將機(ji)(ji)(ji)械力(li)轉(zhuan)(zhuan)(zhuan)化為電(dian)(dian)力(li)。將兩塊(kuai)永(yong)(yong)磁(ci)(ci)(ci)體(ti)相對放置會(hui)產(chan)(chan)生斥力(li)，使(shi)渦(wo)輪旋轉(zhuan)(zhuan)(zhuan)，渦(wo)輪就(jiu)會(hui)轉(zhuan)(zhuan)(zhuan)動(dong)一(yi)個(ge)叫(jiao)做電(dian)(dian)樞(shu)的旋轉(zhuan)(zhuan)(zhuan)線圈，從而產(chan)(chan)生電(dian)(dian)能。自上(shang)世紀(ji)90年代釹(nv)磁(ci)(ci)(ci)鐵變(bian)得更便宜以(yi)來，釹(nv)磁(ci)(ci)(ci)鐵在(zai)許多高(gao)科技應用(yong)中(zhong)取代了早(zao)期的鋁鎳(nie)鈷和(he)鐵氧體(ti)永(yong)(yong)磁(ci)(ci)(ci)。常見用(yong)途包括計(ji)算機(ji)(ji)(ji)硬盤驅動(dong)器、風力(li)渦(wo)輪機(ji)(ji)(ji)、揚聲器/耳機(ji)(ji)(ji)、MRI掃描儀、無(wu)繩工具電(dian)(dian)機(ji)(ji)(ji)；以(yi)及燃油汽(qi)(qi)車(che)、混(hun)合動(dong)力(li)和(he)電(dian)(dian)動(dong)汽(qi)(qi)車(che)的各種電(dian)(dian)機(ji)(ji)(ji)，甚至(zhi)各種工業電(dian)(dian)機(ji)(ji)(ji)。