Force-extension graph reveals material's elastic and plastic behavior up to fracture

Steps:

• Identify key regions: initial linear elastic region where extension is proportional to force (Hooke's law).
• Note yield point: transition to plastic deformation where material permanently deforms.
• Observe nonlinear curve: increasing extension with less force increase until maximum force.
• Locate breaking point: sudden drop in force as material fractures.

Why B is correct:

• Option B depicts the standard force-extension curve with linear elastic, nonlinear plastic, and breaking regions, matching tensile testing up to fracture per material science principles.

Why the others are wrong:

• A shows only linear elastic behavior without plastic deformation or break, incomplete for full testing.
• C lacks a clear yield point and break, misrepresenting real material response.
• D extends linearly indefinitely, ignoring plastic region and fracture, unrealistic for any material.

Final answer: B