1. F from the given graph,
For a stress of 150 × 106 Nm-2
Strain = 0.002
∴ Young’s modulus (Y) = \(\frac {stress}{strain}\)
= \(\frac {150 \times 10^6 Nm^{-2}}{0.002}\)
= 7.5 × 1010 Nm-2.
2. 300 × 106 Nm-2 is the maximum stress that the material can sustain without crossing the elastic limit. Thus, the yield strength of the material is 3 × 108 Nm-2 or 300 × 106 Nm-2.