Question

Consider the following statements:

1. Shear stress is maximum at the centre line.
2. Maximum velocity is $\frac{3}{2}$ times the average velocity.
3. Discharge varies inversely with the coefficient of viscosity.
4. Slope of hydraulic gradient line increases linearly with the velocity of flow.

Which of the above statements are correct in connection with a steady laminar flow through a circular pipe?

• A. 1, 3 and 4
• B. 3 and 4 only
• C. 1 and 3 only
• D. 2 and 4

Answer 1

The correct option is B 3 and 4 only

In a steady laminar flow through circular pipe, the shear stress is maximum at the walls of the pipe.
Its magnitude is given by

${\tau }_0=\frac{8\mu V}{D}$

The maximum velocity is such a case is two times the average velocity.