The amount of energy required to form a soap bubble of radius $2\,cm$ from a soap solution is nearly $..........\,\times 10^{-4}\,J$: (surface tension of soap solution $=0.03\,N\,m^{-1}$)

The work done in blowing a soap bubble of radius $R$ is $W_1$ at room temperature. Now the soap solution is heated. From the heated solution another soap bubble of radius $2R$ is blown and the work done is $W_2$. Then:

The work done in blowing a soap bubble of $10\, cm$ radius is (Surface tension of the soap solution is $\frac{3}{100}\,N/m$).

The surface tension of a liquid is $5 \,N/m$. If a film is held on a ring of area $0.02 \,m^2$,its surface energy is about ........... $J$.

$A$ film of soap solution is formed between two straight parallel wires of length $10 \,cm$ each, separated by $0.5 \,cm$. If their separation is increased by $1 \,mm$ while still maintaining their parallelism, how much work will have to be done? (Surface tension of solution $= 65 \times 10^{-3} \,N/m$)

$1000$ small water drops of equal size combine to form a big drop. The ratio of final surface energy to the total initial surface energy is