Question

Calculate the rise of water inside a clean glass capillary tube of radius 0.1 mm, when immersed in water of surface tension 7x10^-2 N/m. The angle of contact between water and glass is zero, density of water = 1000 kg/m³, g = 9.8 m/s²

Answer 1

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/m³, g = 9.8 m/s²  

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.