A semiconductor is placed in an electric fiel | vedclass

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(B) In a semiconductor,the number density of charge carriers $(n)$ increases exponentially with an increase in temperature because more covalent bonds

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$n$ will increase but $v$ will decrease.

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(B) In a semiconductor,the number density of charge carriers $(n)$ increases exponentially with an increase in temperature because more covalent bonds break,generating more electron-hole pairs.However,the drift velocity $(v)$ is given by $v = \mu E$,where $\mu$ is the mobility and $E$ is the electric field.Mobility $\mu = \frac{e	au}{m}$,where $	au$ is the relaxation time.As temperature increases,the frequency of collisions between charge carriers and the lattice increases,which decreases the relaxation time $	au$.Consequently,the mobility $\mu$ and the drift velocity $v$ decrease as temperature increases.Therefore,$n$ increases and $v$ decreases.

$A$ semiconductor is placed in an electric field. Let the number density of charge carriers be $n$ and the average drift velocity be $v$. If the temperature is increased,then:

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