$A$ crystal has a coefficient of linear expansion $13 \times 10^{-7} \ K^{-1}$ in one direction and $231 \times 10^{-7} \ K^{-1}$ in every direction at right angles to it. Then the cubical coefficient of expansion is:

When a meter rod made of silver at $0^{\circ} C$ is heated to $100^{\circ} C$,its length increases by $0.19 \ cm$. Find the coefficient of volume expansion of the silver.

The coefficient of superficial expansion of a solid is $2 \times 10^{-5} \text{ °C}^{-1}$. Its coefficient of linear expansion is:

Railway tracks are made of steel segments separated by small gaps to allow for linear expansion. $A$ segment of the track is $10 \ m$ long when laid at a temperature of $17^{\circ} C$. The maximum temperature that can be reached is $45^{\circ} C$. The increase in the length of the segment of the railway track is $x \times 10^{-5} \ m$. The value of $x$ is (given $\alpha_{\text{steel}} = 1.2 \times 10^{-5} /{ }^{\circ} C$).

The linear expansion coefficients of brass and steel wires are $\alpha_1$ and $\alpha_2$ respectively,and their lengths at $0^\circ C$ are $L_1$ and $L_2$. If the difference $(L_2 - L_1)$ remains constant at any temperature,then:

The gap between any two rails, each of length $l$ laid on a railway track, is equal to $x$ at $27\,^{\circ}C$. When the temperature rises to $40\,^{\circ}C$, the gap closes up. If the coefficient of linear expansion of the material of the rail is $\alpha$, the length $l$ of a rail at $27\,^{\circ}C$ is: