Question

The valve $V$ in the bent tube is initially kept closed. Two soap bubbles $A$ (smaller) and $B$ (larger) are formed at the two open ends of the tube. $V$ is now opened and air can flow freely between the bubbles.

• A. There will be no change in the size of the bubbles
• B. The bubbles will become of equal size
• C. $A$ will become smaller and $B$ will become larger
• D. The sizes of $A$ and $B$ will be interchanged

Answer 1

The correct option is C $A$ will become smaller and $B$ will become larger

the soap bubbles form due to difference in outside and inside pressure so as the valve V is opened air molecules will move from right to left increasing inside pressure of small bubble and therefore it will further decrease in radius until it bursts. As the excess pressure is inversely proportional to radius of the bubble.