The graph illustrates how the extension of a wire changes as the force varies. The force is increased little by little to a peak at Q and then reduced gradually back to zero at R. Which of the following statements is correct?
- AAlong the line PQ, the wire obeys Hooke’s law.
- BAlong the line RP, the spring constant is equal to $\frac{\text{extension}}{\text{force}}$.
- CThe wire has elastic deformation at point Q.
- DThe work done in stretching the wire to P is equal to $(\text{force} \times \text{extension})$ at point P.