Question

The slope of the stress-strain curve in the elastic deformation region is

• A. Elastic modulus
• B. Plastic modulus
• C. Poisson’s ratio
• D. Bulk modulus

Hint:

The elastic modulus is the ratio of stress to strain in the elastic region of the material’s behavior. It is a measure of the material's stiffness.

Answer 1

The Correct Option is A

The stress-strain curve describes the relationship between stress (force per unit area) and strain (deformation of material). In the elastic deformation region, the material returns to its original shape once the applied force is removed. The slope of this curve in this region is called the Elastic modulus (or Young's modulus). It represents the stiffness of the material and is defined as the ratio of stress to strain in the elastic region, following Hooke's Law: \[ {Elastic Modulus} = \frac{{Stress}}{{Strain}} \] - Option (1) is the correct answer as the slope of the stress-strain curve in the elastic region is indeed the elastic modulus.
- Option (2) Plastic modulus is not relevant here, as plastic deformation occurs beyond the elastic limit, where the material no longer returns to its original shape.
- Option (3) Poisson’s ratio describes the ratio of lateral strain to axial strain but does not directly describe the slope of the stress-strain curve.
- Option (4) Bulk modulus relates to the change in volume under uniform pressure but does not describe the slope in the elastic deformation region of the stress-strain curve.
Thus, the correct answer is the Elastic modulus.