Welding of $$C40$$ steel plate of $$10mm$$ thickness required a current of $$16$$amps, while it was $$360$$amps when the plate thickness was increased by $$50\% $$. Estimate the welding current for $$8mm$$ thickness of same material.

In a typical metal cutting operation, using a cutting tool of positive rake $$\gamma = 10\deg ,$$ it was observed that the shear angle was $$20deg$$. The friction angle is

A cutting tool has a nose radius of $$1.8mm$$. The feed rate for a theoretical surface roughness of $${R_t} = 5$$ microns is

In a turning trail using orthogonal tool geometry, a chip length of $$84mm$$ was obtained for an uncut chip length of $$200mm.$$ The cutting conditions were $$V=30m/min,$$ $${t_1} = 0.5mm,$$ rake angle $$=20deg,$$ cutting tool is $$HSS.$$ Estimate shear plane angle, chip thickness and the shear plane angle for minimum chip strain.