Magnetic field

More conclusions about the creation of magnetic fields

	Coils create a magnetic field with the following intensity: where l is the length of the coil and n is the number of loops. You can tell between the poles by noting that if you look at the north pole, the current circulates counterclockwise.
	A natural magnet behaves like a coil because a significant percentage of the electrons revolve in a preferred direction. The field of a natural magnet affects the electrons in other materials containing iron in such a way that the electrons in the other material change their trajectories. If the electrons go back to their chaotic trajectories when the natural magnet is removed, then the magnetization is temporal, otherwise it is permanent.
	Ampère proved that if we divide a trajectory up into an infinite number of elements and integrate the scalar products of the induction B and each element of the trajectory dl, then the result is proportional to the sum of the intensities of current that flow through the surface limited by the closed trajectory. This law has been very helpful in the theoretical analysis of many magnetic fields.

	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