A.電流的熱效應(yīng)B.電流的磁效應(yīng)C.電磁感應(yīng)D.霍爾效應(yīng)
A.不轉(zhuǎn)B.空轉(zhuǎn)C.運(yùn)轉(zhuǎn)無(wú)力D.異響