Two wires of identical shape but different metals carry different currents at the same voltage because resistivity depends on:

1. Shape alone cannot explain the difference here. 2. The current in a circuit is resisted by the elements of the circuit. 3. The strength of that resistance depends on the material of the elements. 4. Macroscopic properties including resistivity depend on molecular and atomic structure. 5. Identical shapes therefore leave the material as the only difference. _Source: OpenStax College Physics for AP Courses 2e (CC BY 4.0), Ch 20 'Electric Current, Resistance, and Ohm's Law', sections 20.1-20.7_