Correct Answer - Option 1 :
One-half of the maximum velocity
Concept:
In a fully developed laminar flow through circular pipes velocity distribution according to Hagen-Poiseuille’s equation is
\(V = \; - \frac{1}{{4\mu }}\frac{{\partial P}}{{\partial x}}\left( {{R^2} - {r^2}} \right)\)
V is maximum at r = 0,
\({V_{max}} = - \frac{1}{{4\mu }}\frac{{\partial P}}{{\partial x}}{R^2}\)
Average velocity is given by
\({V_{avg}} = - \frac{1}{{8\mu }}\frac{{\partial P}}{{\partial x}}{R^2}\)
⇒ V
avg = V
max/2