$A$ liquid is coming out from a vertical tube. The relation between the weight of the drop $W$,surface tension of the liquid $T$,and radius of the tube $r$ is given by,if the angle of contact is zero.

$A$ thread is tied slightly loose to a wire frame as shown in the figure. The frame is dipped into a soap solution and taken out,such that the frame is completely covered with a soap film. When the portion $A$ is punctured with a pin,the thread:

$A$ $10\, cm$ long wire is placed horizontally on the surface of water and is gently pulled up with a force of $2 \times 10^{-2}\, N$ to keep the wire in equilibrium. The surface tension,in $N/m$,of water is:

When there is no external force,the shape of a liquid drop is determined by

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

$A$ 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 $; N m^{-1}$)