Match the application with type of pattern

Increase in carbon content in plain carbon steels raise its

The type of coated electrode most widely used for welding low carbon steel is

Filler material is ......... A...... in resistance welding and the heat generated in the process is directly proportional to ........ B.........

(A). used / not used$$\,\,\,\,\,\,\,\,\,$$ $$\,\,\,\,\,\,\,\,\,$$ (B). square of the current / cube of the current