Work done in increasing the size of a soap bubble from a radius of $3 \ cm$ to $5 \ cm$ is nearly (Surface tension of soap solution $= 0.03 \ Nm^{-1}$) (in $\pi \ mJ$)

Let $W_1$ be the work done in blowing a soap bubble of radius $r$ from a soap solution at room temperature. The soap solution is now heated and a second soap bubble of radius $2r$ is blown from the heated soap solution. If $W_2$ is the work done in forming this bubble,then:

The surface tension of a liquid is $0.5 \, N/m$. If a film is held on a ring of area $0.02 \, m^2$,its surface energy is:

$A$ big water drop is formed by the combination of $n$ small water droplets of equal radii. The ratio of the surface energy of $n$ droplets to the surface energy of the big drop is

$A$ small liquid drop of radius $R$ is divided into $27$ identical liquid drops. If the surface tension is $T$,then the work done in the process will be

$A$ film of water is formed between two straight parallel wires of length $10 \ cm$ each,separated by $0.5 \ cm$. If their separation is increased by $1 \ cm$ while still maintaining their parallelism,how much work will have to be done? (Surface tension of water $= 7.2 \times 10^{-2} \ N/m$)