A bubble of $8$ mm diameter is formed in the air. The surface tension of soap solution is $30$ dynes/cm. The excess pressure inside the bubble is ........ $dynes/cm^2$

There is a small hole in hollow sphere. Water enters in sphere when it is taken at depth of $40\,cm$ in water. Diameter of hole is ....... $mm$ (Surface tension of water $= 0.07\, N/m$):

A spherical drop of water has radius $1\, mm$ If surface tension of water is $70 \times {10^{ - 3}}\,N/m$ difference of pressures between inside and out side of the spherical drop is ........ $N/{m^{ - 2}}$

Consider the following two statement $A$ and $B$, and identify the correct choice in the given answers

$A :$ The excess pressure inside a small liquid drop is more than that of a big drop.

$B :$ As the aeroplane moves fast on the runway the pressure is more on the upper surface of its wings and less on the bottom surface of the wings.

A cylinder with a movable piston contains air under a pressure $p_1$ and a soap bubble of radius $'r'$ . The pressure $p_2$ to which the air should be compressed by slowly pushing the piston into the cylinder for the soap bubble to reduce its size by half will be: (The surface tension is $\sigma $ , and the temperature $T$ is maintained constant)

The pressure of air in a soap bubble of $0.7\,cm$ diameter is $8\, mm$ of water above the pressure outside. The surface tension of the soap solution is ........ $dyne/cm$