AP EAMCET Engineering 20 Apr 2019 Shift 1 Paper

The water can not enter the pinhole only when the hydrostatic pressure is equal to the excess pressure.
hρg=‌

2T

r

Here, h is the depth upto which the cylinder is immersed, T is the surface tension of the water and r is the radius of the pinhole.
Substituting the given value in above expression, we get
h‌‌=‌

2T

ρgr

‌‌=‌

2×0.07

0.1×10−3×1000×10

‌‌=0.14m
‌‌=14cm