Question

In arc welding operation current value is decided by

Answer 1

In Arc welding, the voltage is directly related to the length of the arc, whereas the current is related to the amount of heat input. Constant current supplies are used for manual welding processes. Example: 1) Tungsten Arc Welding, 2) Shielded Metal Arc Welding. 

Answer 2

In arc value, the heat input amount determines the current used.

The current value increases at a rapid rate when the base material and wire come in close contact to each other.

The direction of the current flow also has a great impact on welding.