Using direct extrusion process, a round billet of $$100$$ $$mm$$ length and $$50mm$$ diameter is extruded. Considering an ideal deformation process (no friction and no redundant work), extrusion ratio $$4$$ and average flow stress of material $$300$$ $$MPa,$$ the pressure $$(MPa)$$ on the $$ram$$ will be

A $$10mm$$ diameter annealed steel wire is drawn through a die at a speed of $$0.5/sec$$ to reduce the diameter by $$20\% $$. The yield stress of the material is $$800MPa.$$

The power required for the drawing process (in $$kW$$ ) is

A $$10mm$$ diameter annealed steel wire is drawn through a die at a speed of $$0.5/sec$$ to reduce the diameter by $$20\% $$. The yield stress of the material is $$800MPa.$$

Neglecting friction and strain hardening, the stress required for drawing (in $$MPa$$) is

By application of tensile force, the cross sectional area of bar $$' P '$$ is first reduced by $$30\% $$ and then by an additional $$20\% $$. Another bar $$'Q'$$ of the same material is reduced in cross sectional area by $$50\% $$ in a single step by applying tensile force. After deformation, the true strain in bar $$'P'$$ and bar $$'Q'$$ will, respectively, be