Figure shows the strain-stress curve for a given material. What are (a) Young's modulus and (b) approximate yield strength for this material ?

(a) As seen from above graph, at the stress of $150\times {10}^{6}N/m^2$ the strain is 0.002. The Young's modulus is given by $Y=\frac{Stress}{Strain}=\frac{150\times {10}^6}{0.002}=7.5\times {10}^{10}N/m^2$

(b) The strain is increased even when stress is reduced after $3\times {10}^{8}N/m^2$, which is the yield strength of the material.