List at least three source of magnetic field
1. Electric current: Moving electric charges create a magnetic field. As the electric current flows through a wire, it generates a magnetic field around the wire.
2. Permanent magnets: Permanent magnets, such as those made from iron, nickel, cobalt or certain alloys, have a magnetic field that emanates from the material. The atomic structure of these materials allows them to retain their magnetic properties.
3. Earth's magnetic field: The Earth itself has a magnetic field that is generated by the movement of molten iron in its core. This magnetic field extends outwards from the Earth's surface and plays a key role in protecting the planet from solar wind and cosmic rays.