Physics (AS & A Level) · Oct / Nov 2018 · Paper 12 · Question 21

A wire has both elastic and plastic properties. When it is slowly loaded, its extension varies with load as shown by line OXY. The removal of the load is represented by line YZ. This creates areas P, Q and R on the graph. Which area represents the maximum elastic potential energy stored in the wire?

1. AP
2. BQ
3. CQ + R
4. DR

As printed in the paper