Question

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.

Answer 1

(a) False - Young's Modulus is defined as
$E=\frac{Stress}{Strain}$
For the same amount of stress, we know that rubber is highly flexible and undergoes a huge change in length compared to steel, hence higher strain.
So, if the strain is higher for rubber, its Modulus has to be low. Modulus indicates the measure of resistance to change in length on the application of stress.

(b) is true because the stretching of coil simply changes its shape without any change in the length of the wire used and shear modulus deals with the change in the shape of the material.