The ease with which a specific type of charged particle moves through a material under the influence of an electric field is referred to as mobility in physics. Electric fields attract these particles, which interact with solid molecules on a regular basis. The average speed at which the particles travel as a result of the electric field and collision is known as drift speed. In most metals, the charge carrier is a negatively charged electron.

Electron mobility is used to determine how rapidly an electron moves through a metal or semiconductor under the influence of an electric field.

Electron mobility is expressed mathematically as: μ=VdE .

Where vd is the electron's drift velocity and E is the external electric field.

The Si unit of mobility is the  m ² v ^-1 s ^-1 .