A.60s比15s B.60s比10s C.60s比5s D.以上說法都不正確
A.會(huì)增大渦流 B.造成局部過熱 C.嚴(yán)重時(shí)還會(huì)造成鐵心失火 D.不會(huì)在螺桿和鐵心間形成短路回路