Drift velocity is the average velocity acquired by charged particles, such as electrons, within a material when influenced by an electric field. The magnitude of drift velocity per unit electric field is defined as mobility. This relationship is given by: m=
|vd|
E
⇒|vd|=m⋅E From this, we understand that: vd∝E Thus, the drift velocity is directly proportional to the electric field E. Therefore, the correct relationship is represented by v∝E.