Question

A soap film is formed in a rectangular frame of length $7\times {10}^{-2}m$ when it is dipped in soap solution. A weight of $0.4\times {10}^{-3}kg$ is required, to pull the frame. Surface tension of the soap solution is

Answer 1

Length of rectangular frame $7cm=0.07m$

Extra weight added is $0.4\times {10}^{-3}kg$

Surface tension is given by

$0.146=0.4\times {10}^{-3}\times 9.81$

$6=0.028N{M}^{-1}$