The work done in blowing a soap bubble of radius 'R' is ' $\mathrm{W}$ '. The work done in blowing a bubble…
The work done in blowing a soap bubble of radius 'R' is ' $\mathrm{W}$ '. The work done in blowing a bubble of radius ' $2 \mathrm{R}^{\prime}$ of the same soap solution is
$\frac{\mathrm{w}}{4}$
$\frac{\mathrm{w}}{2}$
4w
2w
Solution
$\mathrm{W}_{1}=8 \pi \mathrm{R}^{2} \mathrm{~T}$ where $\mathrm{T}$ is surface tension.
If radius is doubled and surface tension remains same then $\mathrm{W}_{2}=8 \pi(2 \mathrm{R})^{2} \mathrm{~T}=8 \pi \mathrm{R}^{2} \mathrm{~T}=4 \mathrm{~W}_{1}$
However, the solution is heated, the value of surface tension decreases. Hence, $\mathrm{W}_{2} < 4 \mathrm{~W}_{1}$