Question

In the following questions, a statement of assertion is followed by a statement of reason. Mark the correct choice as
(a) If both assertion and reason are true and reason is the correct explanation of assertion.
(b) If both assertion and reason are true but reason is not the correct explanation of assertion.
(c ) If assertion is true but reason is false.
(d) If assertion and reason are false.
Q. Assertion: A large soap bubble expands while a small bubble shrinks, when they are connected to each other by a capillary tube.
Reason: The excess pressure inside bubble (or drop) is inversely proportional to the radius.

Answer 1

Correct Answer - A
Since the excess pressure due to surface tension is inversely proportional to its radius, it follows that smaller the bubble, greater is the excess pressure. Thus, when the larger and the smaller bubbles are put into communucation, air starts passing from the smaller into the large bubble because excess pressure inside the former is greater than inside the latter. As a result the smaller bubble shrinks and the larger one swells.