The excess pressure inside a soap bubble of radius 5 mm in balanced by 3 mm column of oil of specific gravity 0.6 Find the surface tension of soap solution.

Answer

`2.205 xx 10^(-2) Nm^(-1)`

Explanation

Here, `R = 5mm = 5xx10^(-3)m ,`
`h = 3mm = 3xx10^(-3)m`
`rho = 0.6 xx10^3 kg m^(-3)` Excess of pressure inside the soap bubble = pressure exerted by 3 mm of oil columm `(4S)/(R ) = h rho g or S = (h rho g R)/(4)`
`:. S = (3xx10^(-3))xx(0.6xx10^3)xx9.8 xx(5xx10^(-3))/(4)`
`=2.205 xx 10^(-2) Nm^(-1)`