Let `2.4 xx 10^(-4) J` of work is done to increase the area of a film of soap bubble from `50 cm^(2)` to `100 cm^(2)`. Calculate the value of surface tension of soap solution.

Explanation

A soap bubble has two free surfaces, therefore increase in surface area
`Delta A = A_2 - A_1 = 2(100 - 50) xx 10^(-4) m^(2) = 100 xx 10^(-4) m^(2)`
Since, work done `W = T xx DeltaA implies T = W/(DeltaA) = (2.4 xx 10^(-4)J)/(100 xx 10^(-4) m^2) = 2.4 xx 10^(-2) Nm^(-1)`.