Drift velocity of an electron per unit applied electric field is called electron mobility.
Mobility of an electron (μ) = Vd/E
Where drift velocity of an electron is given as, Vd = e E τ/m
Mobility of an electron, μ = eτ/m.
E = Electric field intensity.
m = mass of an electron.
τ = Relaxation Time.
Vd = Drift Velocity.
μ = Mobility of an electron.
e = charge of an electron.