Soap Bubbles Contact Interface – Rankers Physics
Topic: Solid and Fluids
Subtopic: Surface Tension and Viscosity

Soap Bubbles Contact Interface

Given below are two statements:
Assertion (A): When two soap bubbles of different radii are brought into contact, the common interface of contact bulges into the bubble of larger radii.
Reason (R): Pressure inside a soap bubble of a lesser radius is more than pressure inside the soap bubble of a larger radius.
 
Both (A) and (R) are true and (R) is the correct explanation of (A).
Both (A) and (R) are true but (R) is not the correct explanation of (A).
(A) is true but (R) is false.
Both (A) and (R) are false.

Solution:

The excess pressure inside a soap bubble is \(P = \frac{4T}{R}\). Thus, pressure is greater inside the smaller bubble (lesser radius). When in contact, the common interface bulges towards the larger bubble due to this pressure difference. Both are true and Reason explains Assertion.

Leave a Reply

Your email address will not be published. Required fields are marked *