Two rods of different materials having coefficient of linear expansion $\alpha_1$and $\alpha_2$ and  Young's modulii $Y_1$ and $Y_2$ respectively are fixed between two rigid massive walls. The rods are heated such that they undergo the same increase in temperature. There is no bending of rods. If  $\alpha_1:\alpha_2= 2 : 3$, the thermal stress developed in two rods are equal provided $Y_1 : Y_2$ is equal to

Two rods are joined between fixed supports as shown in the figure. Condition for no change in the lengths of individual rods with the increase of temperature will be

( ${\alpha _1},\,{\alpha _2},$ = linear expansion coefficient

$A_1, A_2$ = Area of rods

$Y_1, Y_2$ = Young modulus)

A glass flask of volume $200 \,cm ^3$ is just filled with mercury at $20^{\circ} C$. The amount of mercury that will overflow when the temperature of the system is raised to $100^{\circ} C$ is ........ $cm ^3$ $\left(\gamma_{\text {glase }}=1.2 \times 10^{-5} / C ^{\circ}, \gamma_{\text {mercury }}=1.8 \times 10^{-4} / C^{\circ}\right)$

At some temperature $T$, a bronze pin is a little large to fit into a hole drilled in a steel block. The change in temperature required for an exact fit is minimum when

Where $\alpha _V$ is greater among alcohol and mercury ?

Give temperature $^oC$, $^oF$ and $K$ when density of water is maximum.