The point on the pressure-temperature phase diagram where all three phases (solid,liquid,and gas) co-exist is called:

$A$ calorimeter has a water equivalent of $5 \times 10^{-3} \ kg$ and contains $25 \times 10^{-3} \ kg$ of water. It takes $3 \ minutes$ to cool from $28^{\circ}C$ to $21^{\circ}C$. When it is filled with turpentine oil,it takes $2 \ minutes$ to cool from $28^{\circ}C$ to $21^{\circ}C$. The specific heat of turpentine oil is ..... $cal/g^{\circ}C$.

$Assertion :$ In the pressure-temperature $(P-T)$ phase diagram of water,the slope of the melting curve is found to be negative.
$Reason :$ Ice contracts on melting to water.

Two different liquids of same mass are kept in two identical vessels,which are placed in a freezer that extracts heat from them at the same rate,causing each liquid to transform into a solid. The schematic figure below shows the temperature $T$ versus time $t$ plot for the two materials. We denote the specific heat of materials in the liquid (solid) states to be $C_{L1}$ $(C_{S1})$ and $C_{L2}$ $(C_{S2})$,respectively. Choose the correct option given below.

$A$ beaker of height $H$ is made up of a material whose coefficient of linear thermal expansion is $3\alpha$. It is filled up to the brim by a liquid whose coefficient of thermal expansion is $\alpha$. If now the beaker along with its contents is uniformly heated through a small temperature $T$,the level of liquid will reduce by (given $\alpha T << 1$):

The temperature of Bhakhra dam water at the ground level with respect to the temperature at a high level should be: