Question

How to determine the coefficient of viscosity of a liquid by poiseuille's method?

Answer 1

The flow is caused due to pressure difference. Flow rate Q is in direction from high to low pressure. The greater the pressure differential between two points, the greater the flow rate. This relation can be stated by, Q = P2-P1/r.  

Where P1 and P2 are the pressure a two points and R includes everything, except pressure, that affect flow rate.  

The resistance R to laminar flow of an incompressible fluid having viscosity ‘n’ through a horizontal tube of radius ‘r’ and length ‘l’ is given by,

$R=\frac{8nl}{\pi r4}$ this is the equation for Poiseuille’s Law.