Q.
During carbon arc welding

Correct Answer : (C)
Electrode is negative with respect to the work if DC is used

Hints :

During carbon arc welding Electrode is negative with respect to the work if DC is used.

Important Points:

Carbon arc welding is used for welding copper and its alloys.
In this method, the carbon electrode is used which is kept negative with respect to work if DC supply is used.
It is because, if the carbon electrode is made positive, the carbon particles have a tendency to go into the welded joint and make it brittle.
Therefore, the electrode in carbon arc welding is always kept negative and the work positive.

During resistance welding heat produced at the joint is proportional to

The metal surfaces for electrical resistance welding must be