Properties Of Solids And Liquids Question 154
Question: 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.
Options:
A) If both assertion and reason are true and the reason is the correct explanation of the assertion.
B) If both assertion and reason are true but reason is not the correct explanation of the assertion.
C) If assertion is true but reason is false.
D) If the assertion and reason both are false.
E) If assertion is false but reason is true.
Show Answer
Answer:
Correct Answer: A
Solution:
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 in communication, 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.
