IMPORTANT NOTICE
I have no formal education related to electricity or any other branch within the natural sciences. I take no responsibility for the factual accuracy of the posts, comments or any other content within this community.

In previous posts, we have looked at electricity and magnetism separately. However, electricity and magnetism have a close relationship. When current flows through a conductor, magnetic fields appear around the conductor. These are not the same kind of magnetic fields as those that emanate from permanent magnets, which are generated by electron spin. Instead, they are generated by the movement of electrons in the conductor. If the current stops, the magnetic field disappears.

The magnetic fields that are generated around a conductor when they carry current rotate around the exterior of the conductor in certain directions: they rotate clockwise, seen in the direction of the current/electron flow.

The direction of rotating magnetic fields in relation to the direction of current:

Source: https://micro.magnet.fsu.edu/electromag/electricity/generators/ (2026-09-07)

The strength of the magnetic fields waxes and wanes in relation to the amount of current that flows through the conductor. The strength of the magnetic fields is weaker further away from the condctor. If you put a compass next to a single conductor that carries current, the arrow of the compass will position itself perpendicularly to the direction of the current, indicating the direction of the rotation of the magnetic fields.

Compasses next to a current carrying conductor:

Source: https://storage.googleapis.com/dzprtnlcmuyjte/magnetic-field-around-a-wire-experiment.html (2026-09-07)

When looking at cross sections of wires, an "x" and a dot can be used to indicate the direction of current, together with the direction of the magnetic fields. The "x" indicates that the current flows away from the viewer, while the dot indicates that the current flows towards the viewer:

Source: https://www.slideserve.com/tracy/magnetic-field-of-electric-currents (2026-09-07)

The placement of conductors needs to be taken into consideration. Remember what we learned about electron spin! With that in mind, it is easier to understand that if two conductors whose current flows in opposite directions - and thus having magnetic fields rotating in opposite directions - are placed in close proximity to each other, the magnetic fields cancel each other out and no magnetic phenomena is observed outside the conductors. If, however, the conductors are placed so that current flows in the same direction, the magnetic fields amplify each other.
(Illustration needed.)

We can leverage these properties to create strong, non permanent magnets by twisting conductors into spirals or coils. The close proximity of the individual turns in the coil will yield the same effect as if we would have placed several separate conductors whose current flows in the same direction next to each other. We can enhance the strength of the magnetic fields even further by winding the conductor around a piece of iron, keeping the coil shape. The magnetic fields of the coil will then affect the direction of electron spin within the iron and make the iron magnetic. This, in turn, further enhances the magnetic fields of the coil. We call such magnets electromagnets or solenoids.

Simple solenoid construction:

Source: https://www.skyfilabs.com/project-ideas/diy-electromagnet-stem-project-for-school-kids (2026-09-07)

Flow of magnetic fields in a simple solenoid:

Source: https://storage.googleapis.com/dtacjmqtkptxue/what-is-the-difference-between-electromagnet-and-magnet.html (2026-09-07)

One application of electromagnets are in so called relays. Relays are a way to use electromagnetism to turn a switch on and off instead of having to manually flip a switch. The conductor coil with the iron core that we talked about above are seen to the left, in the picture below. Just to the right of that, we see two flaps touching and releasing as current is being applied and removed. When current is applied, the iron core becomes magnetic, pulling the flap just above it downwards. This flap works as lever that actuates the other two flaps to the right.

To be continued.