Why does a moving charge produce a magnetic field around it?

If you are not well-acquainted with special relativity, there is no way to truly explain this phenomenon. The best one could do is give you rules steeped in esoteric ideas like "electromagnetic field" and "Lorentz invariance. read more

The moving charge like electrons produce a dense and complicated imaginary magnetic field that depends on the charge, velocity, acceleration of particle. when the charged particle is in motion, magnetic lines of force rotate around the particle. read more

;) It is unknown why electromagnetism (or, more general, the electroweak force) exists. But it has been observed that it exists and that it satisfies the Maxwell equations. These equations state that a moving charge produces a magnetic field. This is independent of spin. read more

From a different frame of reference (in particular one in relative motion), we'll see the charge moving, thus a current which generates a magnetic field as well. read more