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title: "A cylindrical metallic wire connected to a circuit is heated, causing its temperature to rise. Experimental measurements confirm that the electrical resistivity of the wire increases as the temperature increases. Which of the following provides the best microscopic explanation for this increase in resistivity?"
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url: "https://nerd-notes.com/ubq/121538/"
date_modified: "2026-08-23T05:23:48+00:00"
---

# A cylindrical metallic wire connected to a circuit is heated, causing its temperature to rise. Experimental measurements confirm that the electrical resistivity of the wire increases as the temperature increases. Which of the following provides the best microscopic explanation for this increase in resistivity?

A cylindrical metallic wire connected to a circuit is heated, causing its temperature to rise. Experimental measurements confirm that the electrical resistivity of the wire increases as the temperature increases. Which of the following provides the best microscopic explanation for this increase in resistivity?

- **A.** Thermal energy excites conduction electrons into bound atomic states, which significantly decreases the free charge carrier density within the metal.
- **B.** The number density of free conduction electrons remains nearly constant, but increased thermal vibrations of the lattice ions cause more frequent electron-lattice collisions, reducing the average drift velocity.
- **C.** Thermal expansion increases the cross-sectional area and interatomic spacing of the conductor, which dilutes the macroscopic electric field driving the current.
- **D.** The increased thermal kinetic energy of the electrons increases the net repulsive forces between conduction electrons, preventing them from flowing collectively along the wire.

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