Question

Surface tension of a soap solution is $1.9{10}^{-2}N/m.$ Work done in blowing a bubble of 2.0cm diameter will be

• A. $7.6{10}^{-6}J$
• B. $15.2{10}^{-6}J$
• C. $16{10}^{-6}J$
• D. $2.5{10}^{-6}J$

Answer 1

The correct option is B $15.2{10}^{-6}J$

Work done = Change in surface energy

= Surface Tension $\times$ Area

$=1.910\times$ $4\pi \times {(2\times {10}^{-2})}^2$

workdone = $15.2\times {10}^{-6}J$.