Physics (AS & A Level) · Feb / March 2016 · Paper 12 · Question 19

The Young modulus of steel is twice that of copper. A 50 cm length of copper wire of diameter 2.0 mm is joined to a 50 cm length of steel wire of diameter 1.0 mm, making a combination wire of length 1.0 m, as shown. The combination wire is stretched by a weight added to its end. Both the copper and the steel wires obey Hooke's law. What is the ratio extension of steel wire / extension of copper wire?

1. A4
2. B2
3. C1
4. D0.5

As printed in the paper