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:

On heating water,bubbles formed at the bottom of the vessel detach and rise. Assume the bubbles are spheres of radius $R$ and make a circular contact of radius $r$ with the bottom of the vessel. If $r << R$ and the surface tension of water is $T$,find the value of $r$ just before the bubbles detach. (Density of water is $\rho_{w}$)

The free surface of a liquid has a tendency to contract. This property is called ...... .

Define surface tension with its formula in the context of intermolecular forces.

$A$ straw of circular cross-section of radius $R$ and negligible thickness is dipped vertically into a liquid of surface tension $T$. If the contact angle between the liquid and the straw material is $53^{\circ}$,what is the force acting on the straw due to the surface tension of the liquid? (Given: $\cos 53^{\circ} = 0.6$)

The temperature at which the surface tension of water is zero is: