Fluid Mechanics Viscosity Question 122
Question: Two capillaries of same length and radii in the ratio 1 : 2 are connected in series. A liquid flows through them in streamlined condition. If the pressure across the two extreme ends of the combination is 1 m of water, the pressure difference across first capillary is
Options:
A) $ r_{1}+r_{2} $
B) $ r_{1}^{2}+r_{2}^{2} $
C) $ r_{1}^{4}+r_{2}^{4} $
D) None of these
Show Answer
Answer:
Correct Answer: D
Solution:
$ V=V_{1}+V_{2} $ Þ $ \frac{\pi Pr^{4}}{8\eta l}=\frac{\pi Pr_{1}^{4}}{8\eta l}+\frac{\pi Pr_{2}^{4}}{8\eta l} $ Þ $ r^{4}=r_{1}^{4}+r_{2}^{4} $ \ $ r={{(r_{1}^{4}+r_{2}^{4})}^{1/4}} $
BETA
