A wire is bent in the form of a `U`-shape and a slider of negligible mass is connecting the two vertical sides of the U-shape. This arrangement is dipped in a soap solution and lifted a thin soap film is formed in t he frame it supports a weight of `2.0xx10^(-2) N` if the length of the slider is 40 cm what is the surface tension of the film?

Options

A. `25Nm^(-1)`
B. `2.5Nm^(-1)`
C. `2.5xx10^(-2)Nm^(-1)`
D. `2.5xx10^(-3)Nm^(-1)`

Answer

C

Explanation

`T=(F)/(2l)`