A cylindrical riser of $$6$$ $$cm$$ diameter and $$6$$ $$cm$$ height has to be designed for a sand casting mould for producing a steel rectangular plate casting of $$7cm \times 10cm \times 2cm$$ dimensions having the total solidification time of $$1.36$$ minute. The total solidification time (in minute) of the riser is ___________________

Within the Heat Affected Zone (HAZ) in a fusion welding process, the work material undergoes

A butt weld joint is developed on steel plates having yield and ultimate tensile strength of $$500$$ $$MPa$$ and $$700$$ $$MPa,$$ respectively. The thickness of the plates is $$8mm$$ and width is $$20mm.$$ Improper selection of welding parameters caused an undercut of $$3mm$$ depth along the weld. The maximum transverse tensile load (in $$kN$$) carrying capacity of the developed weld joint is _________________

Better surface finish is obtained with a large rake angle because