This lesson describes how to make a simple electromagnets and a motor that is powered by a solar panel.
A magnet is an object that produces a magnetic field. We are already familiar with certain types of magnetic fields such as the Earth’s magnetic field that a compass uses to point north, or refrigerator magnets that use magnetic fields to stick. Magnets have uses beyond being interesting toys and sticking things on metal, and one of the most widespread uses of magnets in industry is in electric motors. In electric motors, the magnet is used to generate rotation using electrical current passing through loops of wire.
Many of the magnets we are most familiar with are considered permanent magnets. These include common magnets like refrigerator magnets, horseshoe and bar magnets, and rare earth magnets. The magnetic field from these magnets is due to the orientation of electrons in the magnet, which generally does not change.
Another category of magnets that we will explore today is the electromagnet. An electromagnet is a material that normally not magnetic, but when electrical current passes through it, becomes a magnet. A common example of an electromagnet is a curled loop of insulated wire wound like a spring. In an electromagnet, the strength of the magnetic field depends primarily on the amount of current passing through the wire, the number of loops the wire makes in a given distance, and the material the wire is wound around. These magnets are used in many applications including headphones and speakers, motors, and scientific research.
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