The surface energy required to create a liquid surface of area $0.04 \text{ m}^2$ for a liquid of surface tension $75 \text{ N/m}$ will be ....... $\text{J}$

$A$ spherical drop of liquid splits into $1000$ identical spherical drops. If $u_i$ is the surface energy of the original drop and $u_f$ is the total surface energy of the resulting drops (ignoring evaporation),and $\frac{u_f}{u_i} = \left(\frac{10}{x}\right)$,then the value of $x$ is $......$

$A$ water film is formed between two parallel wires of $10 \text{ cm}$ length. The distance of $0.5 \text{ cm}$ between the wires is increased by $1 \text{ mm}$. The work done in the process is (surface tension of water $= 72 \text{ mN/m}$).

The work done in increasing the diameter of a soap bubble from $2 \ cm$ to $4 \ cm$ is (Surface tension of soap solution $= 3.5 \times 10^{-2} \ N/m$)

If $T$ is the surface tension of a soap solution, then the amount of work done in increasing the diameter of a soap bubble from $D$ to $2D$ is: (in $\pi D^2 T$)

The potential energy of a molecule on the surface of a liquid compared to one inside the liquid is