A specimen of metal wire is loaded beyond its limit of proportionality and then unloaded. The force-extension graph for this cycle is shown below, where O→A→B O \rightarrow A \rightarrow B\,O→A→B is the loading path and B→C B \rightarrow C\,B→C is the unloading path.
Which of the following correctly describes what is represented by the shaded area and the distance OCOCOC?
Shaded area: Thermal energy dissipated; Distance OCOCOC: Permanent plastic deformation
Shaded area: Elastic strain energy recovered; Distance OCOCOC: Limit of proportionality
Shaded area: Thermal energy dissipated; Distance OCOCOC: Limit of proportionality
Shaded area: Elastic strain energy recovered; Distance OCOCOC: Permanent plastic deformation