Check if the following statements are True or False:
$(a)$ The magnitude of Young's modulus is proportional to the increase in length.
$(b)$ Breaking stress is known as elasticity.
$(c)$ Quartz is an almost perfectly elastic body.

(C) False. Young's modulus $Y$ is defined as $Y = \frac{FL}{A \Delta L}$. Since $Y$ is a material constant,it is inversely proportional to the change in length $\Delta L$ for a given force,length,and area.
$(b)$ False. Breaking stress is the maximum stress a material can withstand before it breaks; it is not synonymous with elasticity.
$(c)$ True. Quartz is considered to be an almost perfectly elastic material because it shows very little internal friction and returns to its original shape almost completely after the removal of deforming forces.