Q 11-09-154NEETNEET 2022Top questionEasy
If a soap bubble expands, the pressure inside the bubble
Answer: (B) Decreases
A soap bubble has two surfaces, so the inside pressure is
$$P_{in} = P_0 + \frac{4T}{r}$$
As the bubble expands $r$ increases, the excess pressure $\dfrac{4T}{r}$ falls, and the pressure inside decreases (always staying above atmospheric).
Solution by Sreeraj P, M.Sc Physics