Water is filled in a capillary tube of radius `R`. If the surface of water is hemispherical `(theta = 0)`, then find pressure at a point `'A'` which is at `h` depth below the surface.

Explanation

Water is on convex part. So pressure of water just below the surface will be less by `(2T)/(R)`. So pressure at point `A` is `P_(0) (2T)/(R) + pgh`. Her surface of water was hemispherical (contact angle `theta = 0`) so radius of curvature of the surface `=` radius of the tube `= R`.