Hooke’s Law

i. The modulus of elasticity is the slope of stress-strain diagram in the linearly elastic region

ii. Valid upto proportional limit only. Practically elastic and proportional limit are same.

1. Poisson’s Ratio,

i. The lateral strainat any point in a bar is proportional to the axial strain  at that same point if the material is linearly elastic.

ii.  for all practical purpose