# A thin liquid film formed

Question:

A thin liquid film formed between a U-shaped wire and a light slider supports a weight of $1.5 \times 10^{-2} \mathrm{~N}$ (see figure). The length of the slider is $30 \mathrm{~cm}$ and its weight negligible. The surface tension of the liquid film is :-

1. $0.025 \mathrm{Nm}^{-1}$

2. $0.0125 \mathrm{Nm}^{-1}$

3. $0.1 \mathrm{Nm}^{-1}$

4. $0.05 \mathrm{Nm}^{-1}$

Correct Option: 1

Solution: