Question

How is a real fluid in which shear stress is directly proportional to the rate of shear strain called?

• A. Ideal Plastic
• B. Newtonian Fluid
• C. Non-Newtonian Fluid
• D. Ideal Fluid

Hint:

Newtonian fluids have constant viscosity, meaning their flow behavior is predictable.

Answer 1

The Correct Option is B

Step 1: Understanding Fluid Behavior
Fluids are classified based on their response to shear stress.
Step 2: Identifying the Correct Type
- Ideal Plastic: Does not flow until stress exceeds yield value. - Newtonian Fluid: Follows \(\tau = \mu \frac{du}{dy}\), meaning shear stress is proportional to shear strain rate. - Non-Newtonian Fluid: Shear stress is not proportional to shear rate. - Ideal Fluid: Has no viscosity.
Step 3: Conclusion
A Newtonian fluid exhibits a direct proportionality between shear stress and shear rate.