In the deep drawing of cups, blanks show a tendency to wrinkle up around the periphery (flange). The most likely cause and remedy of the phenomenon are respectively,

The force requirement in a blanking operation of low carbon steel sheet is $$5.0$$ $$kN.$$ The thickness of the sheet is $$'t'$$ and diameter of the blanked part is $$'d'.$$ For the same work material, if the diameter of the blanked part is increased to $$1.5d$$ and thickness is reduced to $$0.4t$$, the new blanking force in $$kN$$ is

Match the items in column $${\rm I}$$ and $${\rm I}$$ $${\rm I}$$

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