NEETPhysicsMechanical Properties of Fluids
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): As an air bubble rises from the bottom of a deep lake to the surface, the excess pressure of the air inside it relative to the surrounding water decreases. Reason (R): The excess pressure inside an air bubble is directly proportional to the radius of the bubble. In the light of the above statements
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A)
- BBoth (A) and (R) are correct but (R) is not the correct explanation of (A)
- C(A) is correct but (R) is not correct
- D(A) is not correct but (R) is correct
Correct answer
C. (A) is correct but (R) is not correct
Step-by-step solution
Assertion (A) is correct: As an air bubble rises, the depth of the water column above it decreases, which reduces the external hydrostatic pressure. According to Boyle's law, as the external pressure decreases, the volume of the air bubble increases, meaning its radius R increases. The excess pressure inside an air bubble in a liquid is given by P = 2T R . Since the radius R increases as the bubble rises, the excess pressure P must decrease. Reason (R) is incorrect: The formula P = 2T R shows that the excess pressu