It is desired to make a product having T-shaped cross - section from a rectangular aluminium block. Which one of the following processes is expected to provide the highest strength of the product?

In a metal forming operation when the material has just started yielding, the principal stresses are $${\sigma _1} = \,\, + 180\,\,MPa,\,\,\,$$ $${\sigma _2} = \,\, - 100\,\,MPa,\,\,\,$$ $${\sigma _3} = 0.$$ Following Von Mises' criterion, the yield stress is _____________ $$MPa.$$

Engineering strain of a mild steel sample is recorded as $$0.100\% .$$ The true strain is

The value of true strain produced in compressing a cylinder to half its original length is