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

The maximum possible percentage reduction in area per pass during wire drawing of an ideal plastic material without friction is of the order of

A solid cylindrical stainless steel work piece of $$200mm$$ diameter and $$150mm$$ height. This component is reduced by $$50\% $$ in height with flat die in open die forging. Assuming the flow stress of the material as $$1000$$ $$MPa$$ and the coefficient of friction to be $$0.2,$$ the estimated forging force at the end of the stroke is

A copper strip of $$200$$ $$mm$$ width and $$30$$ $$mm$$ thickness is to be rolled to a thickness of $$25$$ $$mm.$$ The roll of radius $$300$$ $$mm$$ rotates at $$100$$ $$rpm.$$ The average shear strength of the work material is $$180$$ $$MPa.$$ The roll strip contact length and the roll force are