Fluid Mechanics Viscosity Question 324
Question: Radius of a capillary is$ 2\times {{10}^{-3}}m $ . A liquid of weight $ 6.28\times {{10}^{-4}}N $ may remain in the capillary then the surface tension of liquid will be
Options:
A) $ 5\times {{10}^{-3}}N/m $
B) $ 5\times {{10}^{-2}}N/m $
C) $ 5N/m $
D) $ 50N/m $
Show Answer
Answer:
Correct Answer: B
Solution:
[b] $ W=mg=\rho (\pi r^{2}h)g $ $ or,,,W\simeq \rho (\pi r^{2})\times \left( \frac{2T}{\rho rg} \right)g,,,,or,,W=2\pi rT $ $ \therefore ,,,T=\frac{W}{2\pi r}=\frac{6.28\times 10^{4}}{2\pi \times 2\times {{10}^{-3}}}=5\times {{10}^{-2}}N/m $
BETA
