a$)$ Draw a typical Stress$-$Strain diagram for a common metal. Name and briefly explain the main regions and important points on the diagram.

$[5$ marks$]$

b$)$ Two solid cylindrical rods $(1)$ and $(2)$ are joined together at flange B and loaded, as shown in Figure $1$ below. The diameter of rod $(1)$ is D$1\backslash (=24\backslash$mathrm$\{$~mm$\}\backslash ),$ and the diameter of $\backslash (\backslash$operatorname$\{$rod$\}(2)\backslash )$ is D$2=42$ mm $.$ Determine the normal stresses in rods $(1)$ and $(2).[10$ marks$]$

rigure $1$

c$)$ A stainless$-$steel tube with an outside diameter of $60$ mm and a wall thickness of $5$ mm is used as a compression member. If the axial stress in the member must be limited to $340$ MPa $,$ determine the maximum load P that the member can support. $[10$ marks$]$