Q. A model porous block of cross-sectional area (A) and length (L) is made up of N independent capillaries of equal radii (r) and length (L). The porosity of the block is 10%, and the permeability for a laminar, incompressible and steady state flow is 0.02 mD. If the flow is only through the capillaries, then the value of r is____________x 10-6 cm (round off to 1 decimal place). [1 mD = 10-15 m2].
Ans: 3-5
Sol:
k = (ϕr2/8)
0.02 x 10-11 = (0.1r2/8)
r = 4 x 10-6 cm
![Determine the correctness (or otherwise) of the following Assertion [A] and the Reason [R]](https://www.gkseries.com/blog/wp-content/uploads/2023/10/Determine-the-correctness-or-otherwise-of-the-following-Assertion-A-and-the-Reason-R.jpg)
