Answer: It continues to deform without much increase in stress.
- A It returns immediately to original shape
- B It continues to deform without much increase in stress
- C Its stress-strain curve remains a straight line
- D It cannot be stretched at all
Correct answer: B. It continues to deform without much increase in stress
Explanation: Beyond the yield point, plastic materials undergo significant deformation (strain) with little additional increase in stress, before eventually fracturing.
A typical stress-strain curve: the initial straight line (Hooke's Law region, slope = Young's modulus) ends at the elastic limit; beyond the yield point, deformation becomes permanent, peaking at the ultimate tensile strength before the wire finally fractures.
Concept context
Stress, strain, Hookes law, and the elastic moduli that describe how solids deform and recover under load.