Question

The rate of flow of water in one minute through $1m$ length of a capillary tube of internal radius of $1mm,$ if the pressure across the ends of the tube is $5cm$ of Hg is about ( $\eta$ for water is $0.8$ centipoise):

• A. $17ml$
• B. $200ml$
• C. $22ml$
• D. $15ml$

Answer 1

The correct option is B $200ml$

From poiseullis equation,
$Q=\frac{\pi \times {\left(0.2\right)}^{2}5\times 13.6\times 1000}{8\times 0.8\times 100}$
$Q=3.3379c{m}^3/sec$
So,
Rate of flow in 1 minute$=3.3379\times 60mL$
$=200.27mL$
$\approx 200mL$