Fluid Mechanics Viscosity Question 125

Question: Two capillary of length L and 2L and of radius R and 2R are connected in series. The net rate of flow of fluid through them will be (given rate of the flow through single capillary, $ X=\pi PR^{4}/8\eta L) $ [DCE 2005]

Options:

A)3 m/s

B)6 m/s

C)12 m/s

D)8 m/s

Show Answer

Answer:

Correct Answer: C

Solution:

$ a_{1}v_{1}=a_{2}v_{2} $ Þ $ \frac{v_{2}}{v_{1}}=\frac{a_{1}}{a_{2}}={{\left( \frac{r_{1}}{r_{2}} \right)}^{2}} $ Þ $ v_{2}=3\times {{(2)}^{2}} $ = 12 m/s