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Home Q & A Board Science-Related Homework Help Physics
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o.avworo o.avworo
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10 years ago
One of the many underrated marvels of mankind have yet again been put to test under a rigorous course of experimental research with electrical currents. Why does the resistance in graphite (pencil lead) drop when there is a temperature increase? Answer this, and one of life's mysteries will be solved once more.
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#1
10 years ago
Graphite is technically an insulator, meaning that nearly all of it's outer electrons reside in the valence band rather than the conduction band; as temperature increases, the electrons gain energy and more and more travel into the conduction band, meaning more electrons available for conducting charge, hence the resistance of the material decreases.
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#2
10 years ago
I would think due to the fact that the molecules are already in motion due to the heat there would be less resistance in the material. The current would not have to expend excessive energy to move through the the medium.
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