Question

An air bubble in water tank rises from the bottom to the top.which of the following statement are true.

• A. Bubble rises upwards because pressure at the bottom is less than at the top.
• B. Bubble rises upwards because pressure at the bottom is greater than that at the top .
• C. As the bubble rises, its size increase
• D. As the bubble rises, its size decrease.

Answer 1

Answer: (B), (C)

Bubble rises upwards because pressure at the bottom is greater than that at the top .
As the bubble rises, its size increase

Both option B,C
$P_{Bottom}>P_{Surface}$So bubble rises upward.
At constant temperature $V\propto \frac{1}{P}$ (Boyle’s law)
Since
as the bubble rises upward, pressure decreases, then from above law
volume of bubble will increase i.e. its size increases.