A $$2$$ $$mm$$ thick metal sheet is to be bent at an angle of one radian with a bend radius of $$100$$ $$mm.$$ If the stretch factor is $$0.5,$$ the bend allowance is

$$10$$ $$mm$$ diameter holes are to be punched in a steel sheet of $$3$$ $$mm$$ thickness. Shear strength of the material is $$400\,\,N/m{m^2}$$ and penetration is $$40\% $$. Shear provided on the punch is $$2$$ $$mm.$$ The blanking force during the operation will be

A shell of $$100$$ $$mm$$ diameter and $$100$$ $$mm$$ height with the corner radius of $$0.4$$ $$mm$$ is to be produced by cup drawing. The required blank diameter is

A metal disc of $$20$$ $$mm$$ diameter is to be punched from a sheet of $$2$$ $$mm$$ thickness. The punch and the die clearance is $$3\% $$. The required punch diameter is