Surface tension of a soap bubble is 2.0×10-2 Nm-1. Work done to increase the radius of the soap bubble from 3.5 cm to 7 cm will be [Take π=227] [2023]
(3)
Surface area of soap bubble=2×4πR2
Work done=change in surface energy×Ts
=Ts×8π×(R22-R12)
=2×10-2×8×227×49×34×10-4
=18.48×10-4 J