The teeth of both external and internal spur gears can be cut on

During orthogonal turning a steel rod at feed $$0.25$$ $$mm$$ per revolution and depth of cut $$4.00$$ $$mm$$ by a tool of geometry $${0^0},\, - {10^0},\,\,{8^0},\,\,{7^0},\,\,{15^0},\,\,{60^0},\,\,0\,\,(mm)\,\,;$$ the following observation were made: Tangential force $$=1,600N,$$ Axial force in feed direction $$=800$$ $$N,$$ Chip thickness $$=0.60$$ $$mm.$$ Find the coefficient of friction between chip tool interface and shear strength of work material from shear force.

Amount of energy consumption for unit volume of metal removal is maximum in

Increase in rake angle causes ..........A................ in chip thickness and .............B......... in shear angle

(a) increase / reduction
(b) increase / decrease