Magnetic field

The field created by a charged particle

		We already know (as a consequence of Öersted's experiment) that electric currents produce magnetic fields because an electric current affects the behaviour of a compass. The smallest electric current that we can imagine is the current produced by a single charged particle. That is why the following visual studies the field created by a particle in movement:
Note that, in this visual, you will observe the field from two different points of view, because the magnetic field created by a particle is asymmetrical. Hopefully, the visual and your textbook will help you understand the following expression:
	The formula expresses the fact that the particle with charge q and velocity V creates a field B at a point which is defined by the vector R from the position of the particle. The constant μo is known as the magnetic permeability of free space or the magnetic constant.

	by a charged particle
	by a rectilinear current
	by a coil
	An explanation of natural magnetism
	Conclusions

	The generation of alternating currents
	A circuit of alternating current
	Conclusions