The surface tension of $70 \text{ dynes/cm}$ is equal to:

$A$ $10\, cm$ 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:

$A$ drop of liquid of density $\rho$ is floating half-immersed in a liquid of density $\sigma$ and surface tension $T = 7.5 \times 10^{-4} \, N \, cm^{-1}$. The radius of the drop in $cm$ will be: (Take: $g = 10 \, m/s^2$)

Consider a circular ring of radius $1.4 \,cm$ lying on the surface of a liquid. If a vertical force of $0.022 \,N$ greater than the weight of the ring is required to lift this ring from the liquid surface,then the surface tension of the liquid is (in $\,Nm^{-1}$)

Why do colours and lubricating oil have less surface tension?

$Assertion :$ $A$ large force is required to draw apart two glass plates enclosing a thin water film.
$Reason :$ Water acts as a glue and sticks the two glass plates together.