The correct option is B 7.54×10−3 J
Given,
Radius of soap bubble, R=10 cm=0.1 m
Surface Tension, T=0.03 N/m
We know, number of free surfaces for soap bubble, n=2
Work done = surface tension × change in surface area × number of free surfaces
⇒W=T×ΔA×n
=0.03×4π(0.12−02)×2
[ surface area =4πr2 ]
=7.54×10−3 J