# Magnets attract electricity

## Impulse Physics 4, textbook

Magnetic field of a bar magnet (permanent magnet) Magnetic field of an electromagnet Christian Oersted 1 Magnetism as required Cell phone charger, television, computer, drill, fan, electric toothbrush, game console, etc. None of these devices would work without magnetism. The magnets in these devices are not permanent magnets, but so-called electromagnets. Electromagnets convert electrical energy into magnetic energy. The many possible uses of electromagnets make them one of the most important inventions of mankind. There is a magnetic field around a live conductor! You have already learned that a magnet has an attractive effect on certain substances. These are so-called ferromagnetic substances (iron, nickel and cobalt). Magnets have two poles, a north pole (N) and a south pole (S). Poles with the same name (N-N or S-S) repel each other, unlike poles (N-S) attract each other. Permanent magnets, so-called permanent magnets, are magnets that are constantly magnetic. Such permanent magnets are made from ferromagnetic materials or so-called ferrites. A magnet can also be made in a completely different way. There is a magnetic field around a conductor through which electricity flows. The magnetic force can be condensed (compressed) by rolling the conductor into a coil. A coil through which current flows is called an electromagnet. As with a permanent magnet, there is also a north and south pole in an electromagnet. The same applies to electromagnets: poles of the same name repel each other, poles of different names attract each other. You can swap the poles of an electromagnet by changing the direction of the current. Try it yourself with V1! Incidentally, the Danish physicist Christian Oersted discovered the electromagnetic principle quite by accident. While demonstrating an experiment in front of students in 1820, he noticed that the needle of a compass was being deflected by a live wire. He discovered one of the most important physical phenomena of all time. M M How does the compass needle move? Observe + Examine The compass needle is deflected by the magnetic field around the conductor. Caution: Use a DC voltage of no more than 6 V! Check what changes when you change the direction of the current. V1 Materials Compass Cable material Power source (battery) Lightbulb Electromagnets and motors 6 worksheets 6je4mi For testing purposes only - property of the publisher öbv