NATS 1945 Chapter Notes - Chapter 6: Electromagnet, Lodestone, Magnetic Monopole

• School: York University
• Department: Natural Science
• Course: NATS 1945
• Professor: Robin Metcalfe

Document Summary

The source of magnetism is moving electric charge. Since electrons and protons spin, they are tiny magnets. O(cid:271)je(cid:272)ts (cid:271)e(cid:272)o(cid:373)e (cid:373)ag(cid:374)etized (cid:449)he(cid:374) their ele(cid:272)tro(cid:374)s" spi(cid:374) a(cid:454)es are alig(cid:374)ed, either by external magnetic fields or by current. In ferromagnets (e. g. iron), electrons stay aligned after removal of external magnetic field. Since all electrons and protons have 2 poles, mag(cid:374)eti(cid:272) (cid:373)o(cid:374)opoles (cid:272)a(cid:374)"t e(cid:454)ist i(cid:374) (cid:374)or(cid:373)al matter but can be made from electric fields) The carriers of the magnetic force are also electrons and protons, this because the mf arises (cid:449)he(cid:374)e(cid:448)er (cid:272)harged parti(cid:272)les are i(cid:374) (cid:373)otio(cid:374). I(cid:374) the a(cid:271)se(cid:374)(cid:272)e of a(cid:374) e(cid:454)ter(cid:374)al (cid:373)ag(cid:374)eti(cid:272) field, the ele(cid:272)tro(cid:374)s" (cid:373)ag(cid:374)eti(cid:272) fields usuall(cid:455) cancel, leaving the material unmagnetized. These materials are known as ferro(cid:373)ag(cid:374)eti(cid:272) (cid:373)aterials, a(cid:374)d it"s these materials that allow us to create permanent magnets. Magnets you stick on the fridge are made from fm materials. Loadstone is a fm material that gets it (cid:373)ag(cid:374)eti(cid:272) field fro(cid:373) the earth"s (cid:373)ag(cid:374)eti(cid:272) field.