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(D) The drift velocity $v_d$ is given by the formula $v_d = \frac{eE	au}{m}$,where $e$ is the charge of the electron,$E$ is the electric field,$	au$

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decreases,thermal velocity of the electron increases

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(D) The drift velocity $v_d$ is given by the formula $v_d = \frac{eE	au}{m}$,where $e$ is the charge of the electron,$E$ is the electric field,$	au$ is the relaxation time,and $m$ is the mass of the electron.When the temperature of the metal wire increases,the atoms in the metal lattice vibrate with greater amplitude.This leads to more frequent collisions between the electrons and the lattice ions,which decreases the relaxation time $	au$.Since $v_d \propto 	au$,the drift velocity $v_d$ decreases.Additionally,the thermal velocity of the electrons is proportional to the square root of the absolute temperature $(v_{th} \propto \sqrt{T})$,so as the temperature increases,the thermal velocity of the electrons increases.

$A$ metal wire is subjected to a constant potential difference. When the temperature of the metal wire increases,the drift velocity of the electron in it

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