Strain is defined as the change produced within the material that occurs as the result of stress.

Strain is defined as the change produced within the material that occurs as the result of stress.

• A. The reaction within the material that can cause distortion.
• B. The change produced within the material that occurs as the result of stress.
• C. The measure of a metal's hardness.
• D. The ability of a material to return to its original shape.

Answer: (B)

Strain is about how much a material changes in size or shape when a force is applied. It’s the deformation that results from the applied stress, often described as the change in length relative to the original length. That exact idea—the change within the material that occurs due to stress—is what strain means. The other ideas describe different concepts: hardness is about resisting indentation, and elasticity refers to the ability to return to the original shape after removing the load, which describes recovery rather than the deformation itself.

Strain is about how much a material changes in size or shape when a force is applied. It’s the deformation that results from the applied stress, often described as the change in length relative to the original length. That exact idea—the change within the material that occurs due to stress—is what strain means.

The other ideas describe different concepts: hardness is about resisting indentation, and elasticity refers to the ability to return to the original shape after removing the load, which describes recovery rather than the deformation itself.