Wires 1 and 2 are made of the same metal. Wire 2 has twice the length and twice the diameter of wire 1. What is the ratio of resistivities of the wires? Express your answer as wire 2 divided by wire 1.
The resistivity is a property of the material, independently of the dimensions, thus, if both wires are made of the same material, their resistivity is the same. Which means:
