A wire of length L and radius r is clamped at one end. If its other end is pulled by a force F, its length increases by l. If the radius of the wire…

A wire of length $\displaystyle L$ and radius $\displaystyle r$ is clamped at one end. If its other end is pulled by a force $\displaystyle F$, its length increases by $\displaystyle l$. If the radius of the wire and the applied force both are reduced to half of their original values keeping original length constant, the increase in length will become: