$A$ fixed volume of iron is drawn into a wire of length $l$. The extension produced in this wire by a constant force $F$ is proportional to

An object of mass $m$ is suspended at the end of a massless wire of length $L$ and area of cross-section $A$. The Young's modulus of the material of the wire is $Y$. If the mass is pulled down slightly,its frequency of oscillation along the vertical direction is:

$A$ metal bar of length $L$ and area of cross-section $A$ is clamped between two rigid supports. For the material of the rod,its Young's modulus is $Y$ and coefficient of linear expansion is $\alpha$. If the temperature of the rod is increased by $\Delta t ^\circ C$,the force exerted by the rod on the supports is

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

Copper of fixed volume $V$ is drawn into a wire of length $l$. When this wire is subjected to a constant force $F$,the extension produced in the wire is $\Delta l$. Which of the following graphs is a straight line?

$A$ wire of length $2\, m$ is made from $10\, cm^3$ of copper. $A$ force $F$ is applied so that its length increases by $2\, mm$. Another wire of length $8\, m$ is made from the same volume of copper. If the same force $F$ is applied to it,its length will increase by ......... $cm$.