Diagram illustrating generation of electromagnetic field by an electric charge: a static charge (grey small circle at the centre) generates electrostatic field (blue area) which statically extends away into space. A sudden acceleration of the charge (dark blue small circle) creates an electromagnetic pulse (red ring) which radiates away into space at the speed of light, and the space far away still contains the electrostatic field from the time when the charge was stationary (as indicated by grey lines). A charge moving at a constant velocity v generates electric and magnetic field attached with the charge (green area). The field lines (black lines) show the direction and intensity of electric field.³⁾

Magnetic field around a moving electron; the distribution of magnetic field can be calculated from Biot-Savart law⁴⁾