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nokia8650
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Why does current cause an increase in the resistance of a metal wire? Is the below explanation sound?:
As current flows, electrons collide into the atoms of the wire. This causes them to vibrate with a greater amplitude, increasing the temperature. The increased vibration of the atoms results in electrons colliding with the atoms more frequently, increasing the resistance.
Conversely, in a semi-conductor (eg. silicon), the increased temperature causes electrons to be promoted to the conduction band, increasing the number of electrons available for conduction, decreasing resistance since there are more charge carriers per unit volume.
Thanks
As current flows, electrons collide into the atoms of the wire. This causes them to vibrate with a greater amplitude, increasing the temperature. The increased vibration of the atoms results in electrons colliding with the atoms more frequently, increasing the resistance.
Conversely, in a semi-conductor (eg. silicon), the increased temperature causes electrons to be promoted to the conduction band, increasing the number of electrons available for conduction, decreasing resistance since there are more charge carriers per unit volume.
Thanks