In a rolling process, the roll separating force can be decreased by

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