What should be the pressure inside a small air bubble of 0.1 mm radius situated just below the water surface? Surface tension of water is `7.2 xx 10^(-2) Nm^(-1)` and atmospheric pressure is `1.013 xx 10^(5) Nm^(-2)` .

Options

A. `2.012 xx 10^(5) Nm^(-2)`
B. `2.012 xx 10^(4) Nm^(-2)`
C. `1.027 xx 10^(5) Nm^(-2)`
D. `1.027 xx 10^(4) Nm^(-2)`

Answer

C

Explanation

The excess pressure inside the air bubble is given by
`p_(2) - p_(1) = (2S)/(R)`
`:.` Pressure inside the air bubble, `p_(2) = p_(1) + (2S)/(R)`
Substituting the values, we have
`p_(2) = 1.013 xx 10^(5) + (2 xx 7.2 xx 10^(-2))/(10^(-4))`
`= 1.027 xx 10^(5) Nm^(-2)`