Two identical wires of substances $P$ and $Q$ are subjected to equal stretching force along the length. If the elongation of $Q$ is more than that of $P$,then

When a wire of length $L$ clamped at one end is pulled by a force $F$ from the other end,its length increases by $l$. If the radius of the wire and the applied force were halved,then the increase in its length is

The force required to stretch a steel wire of $1\,cm^2$ cross-section to $1.1$ times its original length is $(Y = 2 \times 10^{11}\,N/m^2)$.

The dimensions of four wires of the same material are given below. In which wire will the increase in length be maximum when the same tension is applied?

$A$ load $W$ produces an extension of $1 \ mm$ in a thread of radius $r$. If the load is increased to $4W$ and the radius is increased to $2r$,while all other factors remain the same,what will be the new extension in $mm$?

The pressure that has to be applied to the ends of a steel wire of length $10 \ cm$ to keep its length constant when its temperature is raised by $100 \ ^\circ C$ is: (For steel,Young's modulus $Y = 2 \times 10^{11} \ N/m^2$ and coefficient of thermal expansion $\alpha = 1.1 \times 10^{-5} \ K^{-1}$)