Physics (AS & A Level) · May / June 2022 · Paper 13 · Question 21

The extension of a copper wire is measured for different forces applied to the wire. A graph is plotted to show the variation of the force on the wire against extension. The maximum force is applied at point P. Which statement must be correct?

1. APoint R is the limit of proportionality.
2. BThe elastic potential energy of the wire at point S is given by the area under the graph between points T and S.
3. CThere is no plastic deformation between points Q and P.
4. DThe wire obeys Hooke's law up to a point between R and Q.

As printed in the paper