$A$ wire of length $20 \ cm$ is placed horizontally on the surface of water and is gently pulled up with a force of $1.456 \times 10^{-2} \ N$ to keep the wire in equilibrium. The surface tension of water is (in $N \ m^{-1}$)

Water is filled up to a height $h$ in a beaker of radius $R$ as shown in the figure. The density of water is $\rho$,the surface tension of water is $T$ and the atmospheric pressure is $P_0$. Consider a vertical section $ABCD$ of the water column through a diameter of the beaker. The force on water on one side of this section by water on the other side of this section has magnitude

Consider a spherical drop of radius $R$. The surface tension of the liquid is $\sigma$. The force of surface tension on the shaded sub-hemisphere due to the remaining drop is $0.5\,\pi \sigma R$. The value of the angle $\theta$ (angle subtended by the sub-hemisphere at the center of the drop) is ......$^o$.

What is the ratio of the surface tension force acting on the curved part to that on the flat part?

Give two practical illustrations of surface tension.

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: