The increase in length is $l$ of a wire of length $L$ by the longitudinal stress. Then the stress is proportional to

The elastic limit of brass is $379\,MPa$. What should be the minimum diameter (in $mm$) of a brass rod if it is to support a $400\,N$ load without exceeding its elastic limit?

Explain the spring-ball model of the elastic behavior of solids.

When a load of $80 \,N$ is suspended from a string,its length is $101 \,mm$. If a load of $100 \,N$ is suspended,its length is $102 \,mm$. If a load of $160 \,N$ is suspended from it,then the length of the string is (Assume the area of cross-section is unchanged). (in $\,cm$)

$A$ force of $1000 \, N$ is required to break a copper wire of radius $1 \, mm$. What force is required to break a copper wire of radius $2 \, mm$?

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.