Q. The surface tension of soap solution is $0.03\ {Nm}^{- 1\ }$. the work done in blowing to from a soap bubble of surface area $40\ {cm}^{2},(in\ J),\ is$
A) $1.2 \times 10^{- 4}$
B) $2.4 \times 10^{- 4}$
C) $12 \times 10^{- 4}$
D) $24 \times 10^{- 4}$
Explanation
(b) In case of soap bubble
$W = T \times 2 \times \mathrm{\Delta}A$
$= 0.03 \times 2 \times 40 \times 10^{- 4} = 2.4 \times 10^{- 4}\ J$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.