Question

Radius of a soap bubble is increased from $R$ to $2R$, work done is this process in terms of surface tension is

• A. $ 24\pi {{R}^{2}}T $
• B. $ 12T\pi {{r}^{2}} $
• C. $ 6T\pi {{r}^{2}} $
• D. $ 4T\pi {{r}^{2}} $

Answer 1

Answer: (B)

$ W=T.\Delta A $
$ =T.[4\pi (2{{n}^{2}}-4\pi {{r}^{2}})] $
$ =12T\pi {{r}^{2}} $