List two methods of producing magnetic fields.

Magnetic field:

A zone surrounding a magnet where magnetic force occurs on magnetic materials e.g. iron etc. is called a magnetic field. When a magnetic material$(like\ metal\ or\ charged\ body)$ is placed near a magnet, it experiences a magnetic field.

A magnetic field can be produced by any of these two methods listed below:

(1). By Magnet Bar:

By placing a magnet bar we can produce a magnetic field. Let us take a paper sheet and put it on a bar magnet. Now let us scatter iron filings over the paper. On inspection, it is found that all the iron filling has gathered in the place of the paper under which the bar magnet is kept.

(2). By passing current:

When an electric current is passed through a wire then a magnetic field is produced around the wire which can be seen by placing a small needle near the wire. The needle deflects due to the magnetic field. It proves the current carrying wire is producing a magnetic field.