Question

An air bubble of radius $0.1cm$ is in a liquid having surface tension $0.06N/m$ and density ${10}^{3}kg/m^3$. The pressure inside the bubble is $1100N/m^2$ greater than the atmospheric pressure. At what depth is the bubble below the surface of the liquid? $(g=9.8m/s^2)$

• A. $0.20m$
• B. $0.15m$
• C. $0.1m$
• D. $0.25m$

Answer 1

Answer: (C)

$0.1m$

The excess pressure inside the bubble is given as,

$P_e=\rho gh+\frac{2s}{r}$

$1100={10}^3\times 9.8\times h+\frac{2\times 6\times {10}^{-2}}{{10}^{-3}}$

$h=0.1m$

Thus, the depth of the bubble below the surface of the liquid is $0.1m$.