These magnetic poles behave rather like electric charge s. Poles of opposite kinds attract each other, while poles of the same kind repel. Every magnet is surrounded by an invisible, three-dimensional magnetic field. A field is a region in which something varies from point to point. In a magnetic field, the strength and direction of the magnetic effect varies in a similar way.
The field is at its strongest near the magnet. The idea of a magnetic field is based on the work of British scientist Michael Faraday — in the early 19th century. These helped him to explain many magnetic effects. We now see lines of force as indicating the direction of the field, with their spacing indicating its strength.
Electromagnets are made from wire carrying a current. If the wire is coiled, the fields from each turn of wire produce a stronger field. If the wire is wrapped around an iron core, the field gets stronger still. An electromagnet can be a single coil called a solenoid or bent double, with two coils. Electromagnets make it easy to handle scrap metal.
When the current is switched on, it creates strong magnetism that picks up a load of steel. The crane swings round, the current is switched off, the magnetism disappears, and the steel drops where it is wanted.
Electromagnets have many other uses including the generation of electricity in hydroelectric dams. Need help? How to videos Why join? What are magnets? Most of the magnets you see around you are man-made. Since they weren't originally magnetic, they lose their magnetic characteristics over time. Dropping them, for example, weakens their magnetism, as does heating them, or hammering on them, etc. Air-core magnets are created by current flowing through a wire. That current produces the magnetic field.
Electromagnets are different because they have a ferromagnetic material usually iron or steel located inside of the coils of wire. The core isn't air, it is something that aids in producing magnetic effects, so electromagnets are typically stronger than a comparable air-core magnet.
The Earth is a giant magnet. Its magnetic field is like a bar magnet at its centre. Magnets are usually made from iron or steel , but aluminium , steel-iron , copper , nickel and cobalt can also be made into powerful magnets. Many scientists believe that birds are able to find their way home by using the Earth's magnetic field to guide them on long distance flights.
Some vets use magnets to pick up pieces of wire or other metal from inside the stomachs of large farm animals. For example, we can use magnets to attract iron nails, iron keys, and iron scraps, etc. So in addition to these objects that are obviously composed of iron, what other objects can be attracted to magnets? First of all, let us first analyze the composition of the magnets.
Therefore, the magnet can generate a magnetic field, but only a small part of the metal that can be attracted by the magnet, such as iron, nickel, cobalt, and other magnetophilic metals while most other metals will not be attracted, such as gold, silver, copper, aluminum, tin, lead, titanium , etc. In addition to attracting iron to achieve the effect of removing iron, magnets can also be used in many other fields, such as compasses, attracting small objects, electromagnetic relays, motors, generators, electroacoustics, magnetic Therapy, magnetic levitation, nuclear magnetic resonance, etc.
According to their shapes, magnets can be divided into square magnets, tile magnets, special-shaped magnets, cylinder magnets , ring magnets, disc magnets, bar magnets, etc. According to their components, magnets can be divided into SmCo magnets , neodymium magnets strong magnets , ferrite magnets, AlNiCo magnets, iron-chromium-cobalt magnets, and so on.
According to their applications in the industry, magnets can be divided into magnetic components, motor magnets, rubber magnets, plastic magnets, and so on. Permanent magnets can be natural products, also known as natural magnets, or man-made magnets the strongest man-made magnets are neodymium magnets.
However, non-permanent magnets are magnetic only under certain conditions. For example, an electromagnet has magnetism when it is energized, and the magnetism disappears when it is powered off. It has become magnetized. Other metals, like copper or gold, are not attracted to magnets. Magnets can also attract each other, but only if they face in opposite directions. A magnet has two ends called poles; one end is the north pole and the other is the south pole.
A north pole will attract a south pole; the magnets pull on each other. But the two north poles will push each other away. We say the magnets repel each other. Magnets seem to act something like positive and negative electric charges.
Electricity and magnetism are very closely related. If the words north and south remind you of anything, the earth is in fact a giant magnet.
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