Mechanical Properties of Solids Question Answers: NCERT Class 11 Physics

Exercise 1
Q:
A:

(a) False (b) True

(a) For a given stress, the strain in rubber is more than it is in steel.

Young’s modulus, Y = stress / strain

For a constant stress:  Y ∝ 1 / strain

Hence, Young’s modulus for rubber is less than it is for steel.

(b) Shear modulus is the ratio of the applied stress to the change in the shape of a body. The stretching of a coil changes its shape. Hence, shear modulus of elasticity is involved in this process.