**Calculate the rise of water inside a clean glass capillary tube of radius 0.1 mm, when immersed in water of surface tension 7x****10 ^{-2} N/m. The angle of contact between water and glass is zero, density of water = 1000 kg/m^{3}, g = 9.8 m/s^{2}**

**Calculate the rise of water inside a clean glass capillary tube of radius 0.1 mm, when immersed in water of surface tension 7x****10 ^{-2} N/m. The angle of contact between water and glass is zero, density of water = 1000 kg/m^{3}, g = 9.8 m/s^{2}**

Correct Answer **= 0.142 m**

**Explaination **

**Given::**

r = 0.1 mm = 10^{−4} m,

T = 7 × 10^{−2} N/m,

θ = 0°,

ρ = 1000 kg/m^{3}, g = 9.8 m/s^{2 }

**To find: **Height of capillary rise (h)

**Formula:** h = \(2T\cosθ\over rρg\)

**Calculation:** From formula,

h = \(\frac{2\times(7\times10^{-2})\times \cos 0^o}{10^{-4}\times 10^3\times 9.8}\)

= \(\frac{14 \times10^{-1}}{9.8}\)

= \(\frac{1}{7}\)

**= 0.1429 m **

**The rise of water inside the glass capillary is 0.1429 m.**