A solenoid is a device which is formed when an insulated current-carrying wire is bent into a coil with an N number of loops or turns. It is like wrapping of a wire on a cylindrical object. The individual magnetic field of each turn contribute and it results into a magnetic field which is like the magnetic field of a bar magnet.

The magnitude of magnetic field depends on following factors:

•Number of loop/turns.

•Amount of current.

•Material inside the cylinder.

In these factors amount of current and number of turns play the major role. Both are directly proportional to the magnetic field produced and can be used as a factor to produce strong electromagnetic field.