Fluid Mechanics Viscosity Question 49
Question: Water rises in a capillary tube when its one end is dipped vertically in it, is 3 cm. If the surface tension of water is$ 75\times {{10}^{-3}}N/m $ , then the diameter of capillary will be[MP PET 1989]
Options:
A) 0.1 mm
B) 0.5 mm
C) 1.0 mm
D) 2.0 mm
Show Answer
Answer:
Correct Answer: C
Solution:
$ T=\frac{rh\rho g}{2}\Rightarrow 75\times {{10}^{-3}}=\frac{3\times {{10}^{-2}}\times r\times 10^{3}\times 9.8}{2} $ $ \Rightarrow r=\frac{1}{2}mm $ $ \therefore D=2r=1\ mm $