Question

Drift velocity varies with the intensity of electric field as per the relation

• A. $v_d\propto E$
• B. $v_d\propto \frac{1}{E}$
• C. $v_d=$ constant
• D. $v_d\propto E^2$

Answer 1

The correct option is A $v_d\propto E$

Current , $I$ = $neA{v}_d$

Current density , $J$ = $\frac{I}{A}$ = $ne{v}_d$

Also , current density $J$ is related to electric field $E$

by the relation

$J=\sigma E$

Therefore ,

$ne{v}_d$ = $J=\sigma E$

Hence , $v_d\alpha E$ .