If work done in increasing the size of a soap film from $10\, cm\times6\, cm$ to $60\, cm\times11\, cm$ is $2\times10^{-4}\, J$. What is the surface tension ?

For a constant hydraulic stress on an object, the fractional change in the object’s volume $(\Delta V/V)$ and its bulk modulus $(B)$ are related as

In a $U-$ tube experiment, a column $AB$ of water is balanced by a column $‘CD’$ of oil, as shown in the figure. Then the relative density of oil is

A block of steel of size $5 \times 5 \times 5 \,cm ^3$ is weighed in water. If relative density of steel is $7$ , its apparent weight is ........... $g wt$

Two small drops of mercury, each of radius $R$ coalesce to form a single large drop. The radio of the total surface energies before and after the change is

A cubical block is floating in a liquid with half of its volume immersed in the liquid. When the whole system accelerates upwards with a net acceleration of $g/3$. The fraction of volume immersed in the liquid will be :-