Question

Define mobility of electron.

Answer 1

Electron mobility is the measure of how fast an electron can move through a metal or semiconductor under the influence of external electric field.

Mathematically, electron mobility $\mu =\frac{v_d}{E}$

where $v_d$ is the drift velocity of electron and $E$ is the external electric field.

SI unit of mobility is $m^2{V}^{-1}{s}^{-1}$.