Stress-strain curve is a material property independent of dimensions

Steps:

• Stress is load divided by cross-sectional area; strain is extension divided by original length.
• New wire has length 2L (original L) and diameter d/2 (original d), so area A' = (1/4)A.
• For the same metal, the relationship between stress and strain remains unchanged, as both are normalized quantities.
• Plotting stress vs. strain for the new wire yields the identical curve to the original.

Why B is correct:

• B matches the original graph, per Hooke's law (stress = E × strain), where modulus E is intrinsic to the material.

Why the others are wrong:

• A likely scales stress by area ratio, ignoring normalization.
• C probably stretches strain by length factor, misunderstanding strain definition.
• D may compress or alter the curve, confusing load-extension with stress-strain.

Final answer: B