Draw graph of $\alpha _V$ temperature.

A beaker is filled with water at $4\,^oC$. At one time the temperature is increased by few degrees above $4\,^oC$ and at another time it is decreased by a few degrees below $4\,^oC$. One shall observe that:

When vapour condenses into liquid

Surface of the lake is at $2°C$. Find the temperature of the bottom of the lake…….. $^oC$

The ratio of the coefficient of volume expansion of a glass container to that of a viscous liquid kept inside the container is $1 : 4$. What fraction of the inner volume of the container should the liquid occupy so that the volume of the remaining vacant space will be same at all temperatures ?