$A$ thin flat circular disc of radius $4.5 \,cm$ is placed gently over the surface of water. If the surface tension of water is $0.07 \,N \,m^{-1}$, then the excess force required to take it away from the surface is

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

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

$A$ square frame of side $L$ is dipped in a liquid. On taking out,a membrane is formed. If the surface tension of the liquid is $T$,the force acting on the frame will be (in $TL$)

Two glass plates of area $10^{-2} \,m^2$ have a $10 \,cm$ thick water film between them. The surface tension of water is $70 \times 10^{-3} \,N/m$. The force required to separate the two glass plates from each other is (in $\,N$)

The work done in increasing the size of a soap film from $10 \, cm \times 6 \, cm$ to $10 \, cm \times 11 \, cm$ is $3 \times 10^{-4} \, J$. The surface tension of the film is: