The magnetic field

The magnetic field is a vector field within which all the flux lines have a closed path. In a magnetic field generated by a bar-shaped magnet, two poles can be identified, more precisely the North pole from which the lines of force of the magnetic field exit and the South pole in which the lines of force of the magnetic field enter. Unlike electric fields, in the case of magnetic fields the lines of force are closed. Magnets, if chopped up, tend to form further magnets of smaller dimensions, this is because the North and South magnetic poles cannot be divided in any way. Ferrous materials, if brought close to a magnet in such a way as to enter its magnetic field, undergo the phenomenon of magnetization, that is, they also become magnetic and present on the side with which they are approached a magnetic polarity opposite to that of the permanent magnet. This is the reason why iron is attracted to magnets. If the ferrous materials are then removed from the magnetic field of the permanent magnet, it happens that they lose almost all of the magnetism they previously acquired.