A metallic strip having a thickness of $$12$$ $$mm$$ is to be rolled using two steel rolls, each of $$800$$ $$mm$$ diameter. It is assumed that there is no change in width of the strip during rolling. In order to achieve $$10\% $$ reduction in cross-sectional area of the strip after rolling, the angle subtended (in degrees) by the deformation zone at the center of the roll is

Accuracy of a measuring instrument is expressed as

A machined surface with standard symbols indicating the surface texture is shown in the Figure. (ALL dimensions in the Figure are in micrometer).

The waviness height (in micrometer) of the surface is

If $$E$$ is the modulus of elasticity in $$GPa$$, $$G$$ is the shear modulus in $$GPa$$ and $$v$$ is the Poisson's ratio of a linear elastic and isotropic material, the three terms are related as