Physics (AS & A Level) · Oct / Nov 2025 · Paper 12 · Question 33

A piece of wire X has resistivity ρ, length L and cross-sectional area A. Wire X has a resistance R. A second piece of wire Y is made of a different metal. It has the same resistance as X but has twice the length of X. Which row gives possible values for the resistivity and the cross-sectional area of Y?

1. Aresistivity ½ρ, cross-sectional area ½A
2. Bresistivity ½ρ, cross-sectional area A
3. Cresistivity ρ, cross-sectional area ½A
4. Dresistivity 2ρ, cross-sectional area A

As printed in the paper