试题与答案

如图是一种焊接方法的原理示意图.将圆形待焊接金属工件放在线圈中,然后在线圈中通以

题型:选择题

题目:

如图是一种焊接方法的原理示意图.将圆形待焊接金属工件放在线圈中,然后在线圈中通以某种电流,待焊接工件中会产生感应电流,感应电流在焊缝处产生大量的热量将焊缝两边的金属熔化,待焊工件就焊接在一起.我国生产的自行车车轮圈就是用这种办法焊接的.下列说法中正确的是(  )

A.线圈中的电流是很强的恒定电流

B.线圈中的电流是交变电流,且频率很高

C.待焊工件焊缝处的接触电阻比非焊接部分电阻小

D.焊接工件中的感应电流方向与线圈中的电流方向总是相反

答案:

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