Question

The surface tension of soap solution is $0.03N/m$. The work done in blowing to form a soap bubble of surface area $40c{m}^2$, $\left(inJ\right)$, is

• A. $1.2\times {10}^{-4}$
• B. $2.4\times {10}^{-4}$
• C. $12\times {10}^{-4}$
• D. $24\times {10}^{-4}$

Answer 1

The correct option is B $2.4\times {10}^{-4}$

Work done is given by $W=2T\Delta A$

Where $\Delta A$ is change in area i.e $40c{m}^2$

putting values according to the question:

$W=2\times 0.03\times 40\times {10}^{-4}$=$2.4\times {10}^{-4}$

$W=2.4\times {10}^{-4}J$

Hence option B is correct