QUESTION $1(17$ MARKS$)$

a$.$ Explain briefly how to obtain a stross$-$strain curve. Draw a stress$-$strain curve for a ductile material and show the yiold stross, ultimate stress and Young's modulus on the curve. Also, show the possible true stress$-$strain curve in the same diagram. Briefly explain why the true stress$-$strain curve differs from the engineering stress$-$strain curve.

$($C$01$:PO$1-9$ Marks$)$