$A$ water drop of $0.01 \ cm^3$ is squeezed between two glass plates and spreads into an area of $10 \ cm^2$. If the surface tension of water is $70 \ dyne/cm$,then the normal force required to separate the glass plates from each other will be: (in $N$)

Two soap bubbles have different radii but their surface tension is the same. Mark the correct statement.

The energy needed for breaking a liquid drop of radius $R$ into $n$ droplets each of radius $r$ is (where $T$ is the surface tension of the liquid).

The excess pressure inside a soap bubble of radius $2.5 \text{ cm}$ is $48 \text{ dyne/cm}^2$. The surface tension of the soap solution in $\text{dyne/cm}$ is:

Pressure inside two soap bubbles is $1.01 \, atm$ and $1.03 \, atm$. The ratio between their volumes is (Pressure outside the soap bubble is $1 \, atm$). (in $ : 1$)

The excess pressure inside a soap bubble of radius $0.5 \ cm$ is balanced by the pressure due to an oil column of height $4 \ mm$. If the density of the oil is $900 \ kg \ m^{-3}$, then the surface tension of the soap solution is (Acceleration due to gravity $= 10 \ m \ s^{-2}$)