Elastic limit marks the end of fully recoverable deformation

Steps:

• Elastic limit is the stress beyond which permanent strain remains after unloading.
• In stress-strain graphs, it occurs at the end of the linear region where Hooke's law applies (stress = E × strain).
• Unloading from this point returns to zero strain; beyond it, a residual strain appears.
• Identify the point where the curve deviates from linearity, indicating onset of plasticity.

Why B is correct:

• Point B is at the end of the linear portion, matching the definition of elastic limit where deformation is fully elastic per Hooke's law.

Why the others are wrong:

• A: Lies within linear region, before maximum elastic stress.
• C: In nonlinear plastic region, causing permanent deformation.
• D: Near or at fracture, far beyond elastic behavior.

Final answer: B