A thin liquid film formed between a U-shaped wire and a light slider supports a weight of `1.5xx10^-2N` (see figure). The length of the slider is 30cm and its weight negligible. The surface tension of the liquid film is

Options

A. `0.0125Nm^(-1)`
B. `0.1Nm^(-1)`
C. `0.05Nm^(-1)`
D. `0.025Nm^(-1)`

Answer

D

Explanation

At equilibrium weight of the given block is balanced by force due to surface tension i.e., `2LT=W`
or `T=(W)/(2L)=(1.5xx10^(-2)N)/(2xx.03m)=0.025Nm^(-1)`