# For fluid the shear stress is directly proportional to - (a) strain rate (b) size (c) strain (d) shape

By Ritesh|Updated : November 2nd, 2022

For fluid, the shear stress is directly proportional to the strain rate. The physical characteristic that describes the straightforward fluids' flow resistance is viscosity. According to Newton's law of viscosity, the shear stress of two fluid layers is inversely proportional to velocity differences between them.

### Shear Stress of Fluid

The rate of change of velocity based on the perpendicular distance from the fixed point is directly inversely correlated with shear stress between two fluid layers (Velocity Gradient or rate of deformation or strain rate)

τ α du/dy

τ = μ du/dy

μ = τ/du/dy

where, τ – Shear stress and du/dy - strain rate or velocity gradient.

Summary:

## For fluid the shear stress is directly proportional to - (a)strain rate (b)size (c)strain (d)shape

Shear stress for fluids is inversely correlated with strain rate. For a given pressure and temperature, the ratio of shear stress to rate is constant and is known as the viscosity or coefficient of viscosity.