2021 · Q103
We are given three copper wires of different lengths and different areas of cross-section. Which one of the following would have highest resistivity ?
General KnowledgePhysics
- ACopper wire of 50 cm length and 1 mm diameter
- BCopper wire of 25 cm length and 0.5 mm diameter
- CCopper wire of 10 cm length and 2.0 mm diameter
- DAll the wires would have same resistivity
Explanation
Resistivity is an intrinsic property of the material at a given temperature and does not depend on the wire's length or cross-sectional area (those affect resistance, not resistivity). Since all three wires are copper at the same temperature, all have the same resistivity. The answer is that all wires have the same resistivity.