The surface of soap solution is `25xx10^-3Nm^-1`. The excess pressure inside a soap bubble of diameter 1 cm is

Options

A. 10 Pa
B. 20 Pa
C. 5 Pa
D. none of the above

Answer

B

Explanation

Excess pressure `triangleP=(4T)/(r )`
`=(4xx2xx25xx10^-3)/(1xx10^-2)`
`=20(N)/(m^2)=20Pa` (as `r=(d)/(2)`)