Concept:
For water to stay out of the cylindrical vessel, the excess pressure created inside the water meniscus at the small hole must balance the external hydrostatic pressure from the water column:
\[
h \cdot \rho \cdot g = \frac{2T}{r}
\]
Step 1: Substituting given parameters into the pressure balance equation.
Given parameters:
• Radius of the hole \( r = 0.5 \, \text{mm} = 5 \times 10^{-4} \, \text{m} \)
• Surface tension \( T = 7 \times 10^{-2} \, Nm^{-1} \)
• Density of water \( \rho = 1000 \, \text{kg/m}^3 \)
• Gravity \( g = 10 \, ms^{-2} \)
Step 2: Isolating depth parameter \( h \).
\[
h (1000)(10) = \frac{2 \times 7 \times 10^{-2}}{5 \times 10^{-4}}
\]
\[
h \times 10^4 = \frac{14 \times 10^{-2}}{5 \times 10^{-4}} = 2.8 \times 10^2 = 280
\]
\[
h = \frac{280}{10^4} = 0.028 \, \text{m}
\]
Step 3: Converting to centimeters.
\[
h = 0.028 \times 100 \, \text{cm} = 2.8 \, \text{cm}
\]
This matches option (C) perfectly.