Physics (AS & A Level) · May / June 2020 · Paper 12 · Question 19

A student is investigating the mechanical properties of a metal. He applies different loads to a long thin wire up to its breaking point, and measures the extension of the wire for each load. He then plots a graph of stress against strain. The student repeats the experiment with a wire made from the same metal, with twice the original length and half the diameter. Which graph is obtained?

1. AGraph of stress / 10^6 Pa against strain / 10^-3, with strain axis 0 to 80 and stress axis 0 to 4, same curve shape as original.
2. BGraph of stress / 10^6 Pa against strain / 10^-3, with strain axis 0 to 40 and stress axis 0 to 4, same curve shape as original.
3. CGraph of stress / 10^6 Pa against strain / 10^-3, with strain axis 0 to 80 and stress axis 0 to 16, same curve shape as original.
4. DGraph of stress / 10^6 Pa against strain / 10^-3, with strain axis 0 to 40 and stress axis 0 to 16, same curve shape as original.

As printed in the paper