Question

The adjoining diagram shows three soap bubbles A, B and C prepared by blowing the capillary tube fitted with soap cocks $S_1,S_2$ and $S_3$. With stop cock S closed and stop cocks $S_1,S_2$ and $S_3$ opened.

• A. B will start collapsing with volumes of A and C increasing
• B. C will start collapsing with volumes of A and B increasing
• C. C and A both will start collapsing with the volume of B increasing
• D. Volumes of A, B and C will become equal at equilibrium

Answer 1

Answer: (C)

C and A both will start collapsing with the volume of B increasing

As we know,

Excess pressure inside a soap bubble is inversely proportional to the radius of bubble i.e,
$\Delta P\infty \frac{1}{r}$
This means that bubbles $A$ and $C$ posses greater pressure inside it than $B$. So the air will move from $A$ and $C$ towards $B$.