A thin rod having a length of $1\; m$ and area of cross-section $3 \times 10^{-6}\,m ^2$ is suspended vertically from one end. The rod is cooled from $210^{\circ}\,C$ to $160^{\circ}\,C$. After cooling, a mass $M$ is attached at the lower end of the rod such that the length of rod again becomes $1\,m$. Young's modulus and coefficient of linear expansion of the rod are $2 \times 10^{11} Nm ^{-2}$ and $2 \times 10^{-5} K ^{-1}$, respectively. The value of $M$ is $…….kg .\left(\right.$ Take $\left.g=10\,m s ^{-2}\right)$

Obtain relation between coefficient of volume expansion $(\alpha _v)$ and coefficient of linear expansion $(\alpha _l)$.

A crystal has a coefficient of expansion $13\times10^{-7}$ in one direction and $231\times10^{-7}$ in every direction at right angles to it. Then the cubical coefficient of expansion is

Two rods $A$ and $B$ of identical dimensions are at temperature $30\,^oC$. If a heated upto $180\,^oC$ and $B$ upto $T\,^oC$, then the new lengths are the same. If the ratio of the coefficients of linear expansion of $A$ and $B$ is $4:3$, then the value of $T$ is……..$^oC$

An open vessel is filled completely with oil which has same coefficient of volume expansion as that of the vessel. On heating both oil and vessel,