Question

Which of the following graph shows the relation between shear stress and velocity gradient for a non-Newtonian fluid?

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

For non-Newtonian fluid, the linear relationship between the shear stress and the deformation rate (velocity gradient in parallel flow) as expressed by the $\tau =\eta \frac{du}{dy}$ is not valid. For these fluids the viscosity varies with rate of deformation.
Graph between shear stress vs velocity gradient can be drawn as