Exam 2023 Chemistry question bank (Chemistry)

$A$ wire of length $L$ and radius $r$ is clamped rigidly at one end. When the other end of the wire is pulled by a force $f$,its length increases by $l$. Another wire of the same material of length $2L$ and radius $2r$ is pulled by a force $2f$. Find the increase in length of this wire.

$A$ body of mass $200\,g$ is tied to a spring of spring constant $12.5\,N/m$,while the other end of the spring is fixed at point $O$. If the body moves about $O$ in a circular path on a smooth horizontal surface with a constant angular speed of $5\,rad/s$,then the ratio of the extension in the spring to its natural length will be: