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Why does the electrical conductivity of a metallic conductor decrease as its temperature rises? It is because on heating

1. the lattice atoms vibrate more vigorously
2. the conductor expands
3. the electrons gain energy
4. the electrons vibrate more vigorously

Correct answer: the lattice atoms vibrate more vigorously

Solution

On heating, the positive lattice ions/atoms vibrate with greater amplitude, so the drifting electrons collide more often, reducing relaxation time and hence conductivity.

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