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

Work of $3.0 \times 10^{-4} \, J$ is required to be done in increasing the size of a soap film from $10 \, cm \times 6 \, cm$ to $10 \, cm \times 11 \, cm$. The surface tension of the film is

On what does the value of surface tension depend? Explain.

$A$ pin or a needle floats on the surface of water,the reason for this is:

On what factors does the value of surface tension depend? Explain.

Oil spreads over the surface of water whereas water does not spread over the surface of the oil,due to