Radius of an air bubble at the bottom of the lake is `r` and it becomes `2 r` when the air
Channel: Doubtnut
Date: 2020-08-23

Radius of an air bubble at the bottom of the lake is `r` and it becomes `2 r` when the air bubbles rises to the top surface of the lake. If P cm of water be the atmospheric pressure, then the depth of the lake is