magnetic field penetration

Magnetic field penetration refers to how magnetic fields extend into and through materials. In conductors like metals, free electrons tend to oppose changes in magnetic fields, which initially prevents the magnetic field from deeply entering the material—a phenomenon called the exclusion or "Meissner effect" in superconductors. However, in normal conductors, magnetic fields can penetrate over a certain depth, known as the "skin depth," where the field gradually decreases. This penetration depends on the material's properties and the frequency of the magnetic field, affecting how electromagnetic signals and currents interact with different materials.