Which term describes the ability to permanently deform, usually by stretching along its length?

Which term describes the ability to permanently deform, usually by stretching along its length?

• A. Elasticity
• B. Ductility
• C. Plasticity
• D. Malleability

Answer: (B)

Think about how a material behaves under load and what the phrase “permanently deform, usually by stretching along its length” implies. If a material is permanently deformed, that means it has undergone plastic deformation, not elastic. When the description emphasizes stretching along the length, it points to the ability to be drawn out into a longer form under a tensile load. That specific behavior is known as ductility—the capacity to undergo significant plastic elongation before breaking, often seen as wires being drawn from a metal. Plasticity is the general term for any permanent shape change, but the hint about elongation under tension makes ductility the best fit. Elasticity would mean the material would spring back after removing the load, which isn’t compatible with permanent deformation. Malleability refers to deformation under compression into sheets, not stretching along the length under tension.

Think about how a material behaves under load and what the phrase “permanently deform, usually by stretching along its length” implies. If a material is permanently deformed, that means it has undergone plastic deformation, not elastic. When the description emphasizes stretching along the length, it points to the ability to be drawn out into a longer form under a tensile load. That specific behavior is known as ductility—the capacity to undergo significant plastic elongation before breaking, often seen as wires being drawn from a metal. Plasticity is the general term for any permanent shape change, but the hint about elongation under tension makes ductility the best fit. Elasticity would mean the material would spring back after removing the load, which isn’t compatible with permanent deformation. Malleability refers to deformation under compression into sheets, not stretching along the length under tension.