A.二次諧波 B.正序電壓 C.負(fù)序電壓 D.零序電壓
A.應(yīng)采用同步接通與斷開(kāi)的接點(diǎn) B.應(yīng)采用先斷開(kāi),后接通的接點(diǎn) C.應(yīng)采用先接通,后斷開(kāi)的接點(diǎn) D.對(duì)接點(diǎn)的斷開(kāi)順序不作要求
A.1W B.2W C.5W D.10W