Question

Two soap bubbles of radii r and 2r are connected by a capillary tube-valve arrangement as shown in the diagram. The valve is now opened. Then which one of the following will be the result:

• A. The radii of the bubbles will remain unchanged
• B. The bubbles will have equal radii
• C. The radius of the smaller bubble will increase and that of the bigger bubble will decrease
• D. The radius of the smaller bubble will decrease and that of the bigger bubble will increase

Answer 1

The correct option is D The radius of the smaller bubble will decrease and that of the bigger bubble will increase

It is to be remembered that Pressure inside a bubble is inversely proportional to radii of the bubble. Hence pressure inside a small bubble is more than inside a bigger bubble. which will result in the air to flow from a smaller bubble to the larger one.