Which of the following process can be used for welding of Aluminium alloys
$$P.$$ Submerged arc welding
$$Q.$$ Gas metal arc welding
$$R.$$ Electroslag welding
$$S.$$ Gas tungsten arc welding

Match List - I (welding defects) with List - II (causes) and select the correct answer using the codes given below the lists

In spot pulsed laser welding of aluminium plates (density $$ = 2700kg/{m^3},$$ specific heat $$=896J/kg,$$ melting temp $$=933K,$$ latent heat of melting $$ = 398\,\,kJ/kg)$$ at a temp of $${30^ \circ }C,$$ pulse with energy of $$0.5J$$ is focused onto an area of $$0.05m{m^2}.$$ If the entire energy is coupled into the material, what will be the depth of weld assuming the $$CS$$ area of the weld is circular and is uniform throughout its depth and only heat conduction in the direction of penetration