The maximum force,in addition to the weight,required to pull a wire of $5.0 \, cm$ long from the surface of water at a temperature of $20^\circ C$ is $728 \, dynes$. The surface tension of water is:

$A$ $U$-shaped wire is dipped in a soap solution and removed. The thin soap film formed between the wire and the light slider supports a weight of $1.5 \times 10^{-2} \; N$ (which includes the small weight of the slider). The length of the slider is $30 \; cm$. What is the surface tension of the film?

$A$ circular film of a liquid has an area of $10 \,cm^2$. If the work done in increasing its radius to two times the initial radius is $8 \times 10^{-3} \,J$, the surface tension of the liquid is $\left(1+\frac{1}{\alpha}\right) \,N/m$. The value of $\alpha$ is

How does the surface tension of a liquid change with temperature?

Soap helps in cleaning clothes,because

What is the effect of increasing temperature on surface tension?