Question

List three sources of magnetic field.

Answer 1

Hint:The main sources of magnetic field are permanent magnet, current carrying conductor and electromagnet. A magnetic field is created whenever the charge is in motion.

Complete answer:
The sources of magnetic field as follows:
1) Permanent magnet: Permanent magnet behaves as a source of magnetic field because the atom inside the permanent magnet consists of both electrons and nucleus. The electron revolving around the nucleus in its orbit creates a magnetic field. So the magnetic field of a permanent magnet is a sum of the magnetic field of the electrons revolving about the nucleus in their orbit, the electron spin, the nucleus spin and even the orbit spin.
2) Current carrying conductor: All moving charge produces magnetic field. The current carrying wire consists of moving charges and therefore produces a circular magnetic field around itself.
3) Electromagnet: A magnet in which a magnetic field is produced using electricity is known as electromagnet. An electromagnet consists of a wire wound around a magnetic core usually made up of ferromagnetic or ferrimagnetic substance like iron. A magnetic field is produced when current is passed through this wire. But this magnetic field is temporary and disappears as soon as electric current stops flowing.

Note:
The magnetic field created by a source may be temporary or permanent. Permanent magnet is a permanent source of magnetic field and produces a strong magnetic field where a magnet is a temporary source of magnetic field. Right hand rule is used to find the direction of magnetic field in a current carrying wire.