15) Which is the welding process that maintains electric arc between non-consumable tungsten electrode and the base metal?

16) What is the name of the defect in which the weld metal did not melt with base metal in TIG process?

17) What is the bore dia of ceramic nozzle to avoid porosity while doing TIG, welding?

18) How to avoid burning fast of tungsten in TIG welding process?

19) Which part the equipment the electron beam is direct and controlled in an electron beam welding process?