The diagram above illustrates a beaker of water being heated. It is observed that as the bubbles rise they get bigger in size.The reason for this observation is
A.
water pressure on the bubbles decreases
B.
density of water increases with rise in temperature
C.
volume of water increases with rise in temperature
D.
atmospheric pressure on the bubbles decreases
Correct answer is A
When a bubble is deep under water, it has both atmospheric pressure and water pressure (giving it depth), acting on it but as it rises, the water pressure decreases. At this point, the basic pressre acting on the bubble is the atmospheric pressure. Recall that pressure is inversely proportional to volume (Boyles' law), hence, the less the pressure, the more the volume