$A$ bubble from the bottom of a lake rises to its surface. Its volume doubles in the process. Assuming isothermal conditions, atmospheric pressure $= 75 \, cm$ of $Hg$, and the ratio of the densities of mercury and water $= 40/3$. The depth of the lake will be ..... $m$.

$A$ liquid $X$ of density $3.36 \, g/cm^3$ is poured into a $U$-tube containing $Hg$ up to a height of $10 \, cm$. Another liquid $Y$ is poured into the left arm to a height of $8 \, cm$. The upper levels of $X$ and $Y$ are at the same height. Find the density of liquid $Y$ in $g/cm^3$. (Density of $Hg = 13.6 \times 10^3 \, kg/m^3$)

Two liquids of densities $\rho_1 = 1$ and $\rho_2 = 2$ are mixed in equal masses. What is the density of the resulting mixture?

Two immiscible liquids $A$ and $B$ are kept in an $U$-tube. If the density of liquid $A$ is smaller than the density of liquid $B$,then the equilibrium situation is

What is absolute pressure? And what is gauge pressure?

Which of the following quantities is expressed as force per unit area?