Read the following two statements below carefully and state, with reasons, if it is true or false.

(a) The Young’s modulus of rubber is greater than that of steel;

(b) The stretching of a coil is determined by its shear modulus.

(a) False.

Please be informed that the strain factor in rubber material is higher than the strain in the steel material. The young’s modulus is inversely proportional to the strain.

Hence, the Young’s modulus of steel is greater than that of rubber.

(b) True.

In material science, shear modulus or modulus of rigidity, denoted by G, or sometime S or μ, is defined as the ratio of shear stress to the shear strain.

The stretching of coil simply changes its shape without any change in the length of the wire used in the coil due to which shear modulus of elasticity is involved.