Question

Under what condition of fluid flow does shear stress NOT exist?

• A. Fluid in low velocity motion
• B. Fluid in high velocity motion
• C. Negligible viscosity
• D. Relative motion exists between fluid layers

Answer 1

Answer:

C. Negligible viscosity

Shear stress does not exist in an ideal fluid with negligible viscosity, where there is no motion between hypothetical liquid layers. This is due to the absence of friction force.