Arrange the following liquids in increasing order of surface tension: Water,Mercury,Soap solution.

$A$ thin liquid film formed between a $U$-shaped wire and a light slider supports a weight of $1.5 \times 10^{-2} \; N$ (see figure). The length of the slider is $30 \; cm$ and its weight is negligible. The surface tension of the liquid film is (in $; N m^{-1}$)

What tendency do molecules on the surface of a liquid possess?

The force required to take away a flat circular plate of radius $2 \ cm$ from the surface of water is $[$ Surface tension of water $= 70 \times 10^{-3} \ Nm^{-1}, \pi = \frac{22}{7} ]$

Oil spreads over the surface of water whereas water does not spread over the surface of the oil,due to

Soap helps in cleaning clothes,because