It is easier to spray water to which soap is added because the addition of soap to water:

Consider a water tank shown in the figure. It has one wall at $x=L$ and can be taken to be very wide in the $z$ direction. When filled with a liquid of surface tension $S$ and density $\rho$,the liquid surface makes an angle $\theta_0 \left(\theta_0 \ll 1\right)$ with the $x$-axis at $x=L$. If $y(x)$ is the height of the surface,then the equation for $y(x)$ is:
(Take $\theta(x) \approx \sin \theta(x) \approx \tan \theta(x) = \frac{dy}{dx}$,where $g$ is the acceleration due to gravity.)

The unit of surface tension in the $SI$ system is

Assertion $(A)$: At critical temperature,the surface tension of liquids becomes zero.
Reason $(R)$: At critical temperature,the intermolecular forces for liquids and gases become equal.

Why does the free surface of a liquid tend to contract?

$A$ spherical body of density $\rho$ is floating half immersed in a liquid of density $d$. If $\sigma$ is the surface tension of the liquid,then the diameter of the body is