It is similar to electric current. When electrons spin, they create a small dipole. The net force of these spins can be negligible if the spins are balanced. On the other hand, if there are many unpaired elements, then the magnetic moment can become very large. Magnetic fields are created around metals as a result of this process.
Electric currents can also produce magnetic fields. An electric current passing through a wire creates a circular magnetic field. The magnetic field created by an electric current near a conductor of power can also be used to create electric currents. It has led to the discovery of many innovative devices and applications that make use of magnetism and electricity. Electromagnetic theories explain so much of modern technological advancement. What Magnets are Available There are many types of magnets.
A magnetic metal can be distinguished by how long its properties remain active. As a result, magnets can be classified into the following categories: Permanent Temporary Electromagnets Permanent Magnets Permanent magnets come to mind when talking about magnets.
A magnetic field can be created by magnetising these objects. As a perfect example, the refrigerator magnet, which commonly hangs notes on the refrigerator door. Most permanent magnets contain iron, nickel, or cobalt. Permanent magnets are made from two types: "Hard" and "soft" magnets. Magnetic metals that are "hard" tend to remain magnetised for a long time.
The following are some common examples Alnico is an alloy made up of aluminium, nickel and cobalt. A strong permanent magnet can be made from Alnico alloys.
Consumer electronics and industrial applications use them extensively. The material is found for example in large electric motors, microphones, loudspeakers, electric guitar pickups, and microwaves. Ferrite is a ceramic compound composed of iron oxide and other elements Strontium or Barium.
Among the applications of ferrites are refrigerator magnets and small electric motors. Neodymium magnet NdFeB is a type of rare-earth magnet that is composed of a neodymium, iron, and boron alloys. General Motors and Sumitomo Special Metals invented them in The strongest permanent magnets currently available are neodymium magnets.
Among their applications are cordless tools, hard disk drives, and magnetic fasteners. Samarium Cobalt alloys are also rare earth magnets, often used in specialist applications such as aerospace. The magnetisation of "soft" magnetic metals is possible, but they lose their magnetism quickly. Typical examples include iron-silicon alloys and nickel-iron alloys. Materials such as this are typically used in electronics, for example in transformers and magnetic shielding.
The internal structure of permanent magnets creates magnetic fields. They are usually not prone to losing their magnetism easily. Ferromagnetic metals can be made into permanent magnets that do not lose their magnetic field, regardless of external influences. They can withstand demagnetising forces, and are thus stable. The internal structure of magnet materials is key to understanding permanent magnets.
When domains of a material are lined up in the same direction, they display magnetic properties. Domains are tiny magnetic sources within the structure of a material. The domains of ferromagnetic material are aligned in strong magnets. The Earth's core behaves like a permanent magnet because of similar conditions present inside it. Temporary Magnets A temporary magnet is a magnet that acts like a permanent magnet when in a magnetic field, but loses its magnetic properties when out of a magnetic field.
Under certain conditions, temporary magnets preserve their magnetic properties. If these conditions no longer exist, the magnetic fields will disappear. Examples of temporary magnets include soft materials with low magnetic properties, such as annealed iron and steel.
In the presence of a strong magnetic field, they become magnetic. Their coercive power is low. If you've ever seen paper clips stuck together when a permanent magnet is nearby, then you know how it works. Magnetic fields can cause paper clips to become temporary magnets attracting other paper clips. In the absence of the permanent magnet, the paper clips lose their magnetic properties. Electromagnets Magnetic fields are generated by electro magnets as electric current passes through them.
Their applications are diverse. As an example, motors, generators, relays, headphones, etc. Electromagnets have a ferromagnetic core surrounded by a coil of wire.
By connecting the wire to a source of electricity, a strong magnetic field is created. When it comes to ferromagnetism, only very few elements are ferromagnetic, including iron, cobalt, and nickel. When people talk about magnetic materials, they usually mean ferromagnetic materials because that is the only type of magnetism easily observed in daily life. When a permanent magnet sticks to a fridge, a paper-clip, or a pan, it is ferromagnetism at work.
The original question was probably meant to be "Why are all metals ferromagnetic? In terms of objects readily found in a house, the ones that stick to a permanent magnet do so because they probably contain iron, nickel, or cobalt.
Considering that steel is such a common building material, and steel contains mostly iron, most of the magnetism experienced outside laboratories is due to iron. In fact, this is where ferromagnetism gets its name.
The word "ferro" means iron in Latin. Like an electric current, magnetism is caused by electrons at the elementary level. Electrons have spin, which creates a tiny magnetic dipole. When these spins are balanced, the net force is zero. But in case of a large number of unpaired electrons, this infinitesimally small magnetic moment becomes large. As a result, it creates a noticeable magnetic field around the metal.
Electric current is also capable of creating magnetic fields and vice versa. When an electric current passes through a wire, it creates a circular magnetic field around the wire. Similarly, bringing a magnetic field near a good conductor of electricity, electric currents start flowing in the conductor. This amazing relationship between electricity and magnetism has resulted in many ingenious devices and applications.
There are various classifications for magnets. One way to differentiate magnetic metals from each other is by how long their properties are active.
Using this as our basis, we can classify magnets as:. Permanent magnets produce a magnetic field due to their internal structure. They do not lose their magnetism easily. Permanent magnets are made of ferromagnetic materials that do not stop producing their magnetic field regardless of external influence. Thus, they are stable against demagnetising forces. To understand permanent magnets, we must look at the internal structure of magnetic materials.
A material displays magnetic properties when its domains are aligned in the same direction. In ferromagnetic materials, the domains are perfectly aligned. There are various ways to align them but the most reliable method is to heat the magnet to a certain temperature. This temperature is different for materials and results in the permanent alignment of domains in one direction. Temporary magnets, as the name suggests, only retain their magnetic properties under certain conditions.
When these conditions are no longer present, they lose their magnetic fields. Soft materials with low magnetic properties, such as annealed iron and steel, are examples of temporary magnets.
They become magnetic in the presence of a strong magnetic field. They also portray low coercivity. You must have seen how paper clips get attached to each other when a permanent magnet is nearby. Every paper clip becomes a temporary magnet attracting other paper clips in the presence of a magnetic field.
Once the permanent magnet is taken away, the paper clips lose their magnetic properties. Electromagnets are magnets that produce magnetic fields when an electric current passes through them. They have various use-cases. For example, motors, generators, relays, headphones, etc.
In electromagnets a coil of wire winds around a ferromagnetic core. Connecting the wire to a source of electricity produces a strong magnetic field.
The ferromagnetic material further amplifies it. Electromagnets can be extremely strong depending on the electric current. They also provide the ability to turn the magnetic force on and off with the press of a button. This is an extremely special property that helps us to use the magnetic force in our applications. With the help of an electromagnet, we can pick up the scrap metal by passing an electric current through it.
When we need to drop the pieces, all we have to do is turn off the electricity to the magnet. Another interesting example of an electromagnet application is the Maglev train.
In this application, a train lifts off the tracks and levitates. It is only possible when an electric current runs through electromagnets on the train body.
This considerably reduces the resistance faced by the train when in motion. Hence, these trains have very high velocities.
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