You have probably come across magnets of different types in and around the house.
Playing with magnets is one of the first things you see children enjoying playing with.
Magnets are safe to play with, fun, and easy to use too, and they are quite impressive also! Magnets are seen mostly holding up notes and photos on refrigerators, and they come in different shapes from round discs, horseshoes, and rectangular bars.
Kids use magnets for playing. A magnet is an exceptional metal that creates an invisible force called magnetism.
A magnet has two ends, a north and a south pole, which are the most vital parts of a magnet.
The regions surrounding the north and south poles are called a magnetic field, which is the place where other objects and charged particles get drawn to the magnet.
Magnets are ubiquitous in our day to day lives, in different shapes and sizes, and they vary from ferrite, Alnico, to neodymium magnets. Ferrite magnets are the ones used to fix refrigerator magnets.
Magnet Facts for Kids
- A magnet has two ends called poles: the North Pole and the South Pole.
- A magnet creates an invisible three-dimensional area of magnetism called a magnetic field.
- If you attach a piece of wood to a bar magnet and let it float in water, it slowly turns so that the North Pole of the Magnet faces the earth’s North Pole.
- The earth’s surface is believed to be an alloy of iron and nickel, which gives the earth its magnetic field.
- The North Pole of one magnet pushes away and repels another magnet is the North Pole and vice versa.
A magnet refers to an object that can pull certain metals towards itself or push them away, hence attraction and repelling. Magnets have an invisible force which is a characteristic of most magnetic objects, known as magnetism.
Magnetism is a primary force of nature just like electricity or gravity. Even though it is not possible to see this force, we can see the effect of the energy over a distance and the things around the magnetic field.
Alloys containing metals that have specific magnetic properties make up most magnets. However, not all metals are magnetic, only a few rare-earth metals like cobalt, iron, nickel, and neodymium. There are some metals like copper and aluminium that aren’t attracted to magnets.
History of Magnets
Magnets have been around for thousands of years, and it is believed that magnetite, the first naturally occurring materials, were discovered first in Turkey by Ancient Greece.
It is believed to have first been seen when a Greek shepherd named Magnes had his crook, which had a strip made of iron stuck on a Lodestone rock he was standing on.
Lodestone was a rock containing mineral magnetite that was used by the Chinese to make compasses millennia ago.
Magnets seemed like magic to the ancient people, and it is only until recently has science explained why and how magnets work. The first people to use lodestones, the common name given to the magnetite magnets in ancient times were the Vikings.
They needed the compasses made for navigation across the water through harsh conditions. They did this to discover and to take possession of new conquest lands. Some people believe that the Vikings kept magnetic compasses from people and as a secret for a long time, but they are now used in most ships to navigate open seas.
A magnetic compass was an essential and very simple tool consisting of a balancing magnet, known as a needle which had one end marked N to indicate North. The magnetic needle was always drawn to the North magnetic pole, a result of earth’s magnetic field, and it doesn’t necessarily point to the true North but rather to the magnetic North Pole.
Another theory attributed to the discovery of magnets is Archimedes, an Ancient Greece scientist supposedly pulled nails out of the ships of his enemy using lodestone, which caused the vessel to come apart, subsequently sinking.
Some people believe that the Chinese were the first to discover lodestones, the naturally occurring magnetic rocks. The Chinese initially used these magnetic rocks for magic tricks and fortune-telling, after which they used the lodestone for the invention of the compass.
How does magnetism work?
Magnets are divided into permanent and temporary or soft magnets, with the latter retaining their charge unless in the event of demagnetizing. Temporary or soft magnets are considered induced, and they only acquire magnetic properties when they are in close contact with a permanent magnet. They lose their magnetism as soon as the connection is lost in most cases.
Magnets are made using materials that make up a magnetic field, and they can be found in most of the electronic devices. Things that have motors such as televisions, and microwave ovens all use a magnet to operate.
Magnets are useful in ensuring refrigerator doors remain locked, in trains, they are mounted on trucks cleaning roads and in systems used in slowing down roller coasters.
Magnets attract objects such as scissors, bolts, paper clips, nuts, and screws, and will repel rubber, plastic, or wood. Magnets have two poles, a north and a south pole. The like poles of a magnet repel, so the north pole will push away another magnet’s north pole, and the south pole will repel the south pole of another magnet.
An interesting fact about magnets and their poles is that you end up with two identical magnets if you cut a magnet in half. Each of these magnets has a south pole and a north pole, which means no magnet has a single north pole and a single south pole.
Magnetic materials attract magnets, and they are composed of many small magnets known as magnetic domains.
Most metals are attracted to magnets, and they may magnetize when exposed to a magnetic field. Steel is the most common magnetic material found on earth, a mix of iron, carbon, and other metals.
Steel makes a permanent magnet because it stays magnetized once magnetized. The two ends of a magnet are not the same, with the north and south poles behaving like electric charges. Unlike poles attract each other, while poles repel.
Types of magnets
All magnets are surrounded by a three-dimensional and invisible magnetic field
There are two different kinds of magnets permanent, and induced magnets.
Permanent magnets are also known as hard magnets. Unlike induced, soft, or temporary magnets, they always have their magnetic forces that get magnetized temporarily when they are put near a permanent magnet.
Permanent magnets are mostly manufactured, and they have ferromagnetism. These magnets are however found occurring naturally in rocks like a lodestone. Magnets are attracted to special metals, and cobalt, nickel, and iron are magnetic.
It is also possible for metals with iron to attract magnets, such as steel. There are exceptional metals like zinc, brass, copper, and aluminum that are not attracted to magnets. Other materials like glass and wood are non-magnetic, meaning that they lack any magnetic material in them and they are called non-magnetic materials.
Iron is the metal most people think about when they hear magnetic materials. Hence it’s considered the king of magnets, and not the only magnetic metal. There are other rare-Earth elements and metals like Cobalt and Nickel, which make perfect magnets.
Some of the best magnets in the surface of the earth are alloys, meaning that they are mixtures of these elements with one or more of each other.
Iron filings are an excellent example of a temporary magnet when a magnet is placed near them, but they end up losing some or all of their magnetism when the magnet is taken away. As such, iron is considered a magnetically soft material, but on the contrary, the alloys of iron and rare-Earth elements hold back most of their magnetism even when the source of the magnetic field is pulled away.
Soft magnets are considered impenetrable, and they are used commonly in electromagnets. These magnets are used in the enhancement of the magnetic field, usually hundreds of thousands of times.
The field of the soft magnet increases as the electrical current increases too.
Properties of magnets
When a magnet is exposed to a hot flame, it loses its magnetization, a process known as demagnetization. This is because the molecules get mixed up and are no longer aligned in a north-south pattern.
The like poles of a magnet repel, (north and north pole; south and south pole), while unlike bars attract (north and south poles). This is the fundamental law of magnets, which can be demonstrated by placing together two magnets’ poles, if they pull together, then the opposite poles face each other. If they push away, then the like poles are facing each other.
Uses of magnets
Magnets are fascinating, and they are used for their magnetic properties and fun as well. Looking around, there are many things at home and in our surroundings made of magnets. Things are operating as a result of electromagnetism or magnetism as well. One of the earliest uses of magnets was magnetic compasses, where they were used for navigation by ancient Greece.
Magnets are today found and used in different places. Electric appliances with motors use magnets to convert electricity into motion, such as electric toothbrushes and mowers. The motors in these electric appliances use electricity to create temporary magnetism in wire coils, making the motion used in driving machines.
Magnets are used to hold refrigerator doors closed. Magnets are used in kitchens to keep the refrigerator door shut when needed, and a refrigerator magnet is also used for decorations kids play with on refrigerator doors.
Magnetic force can function without necessarily making any contact, unlike the pulling and pushing forces. It is important to note that, even though magnetic materials are usually metals, not all metals are magnetic.
Magnets are used to record media such as VHS tapes and the regular audio cassettes that depend on magnetic tapes. The information used in making the sound and video is usually encoded on the tape’s magnetic coating, which is similarly used in hard disks and floppy disks for recording data.
They can read and write data on these cassette tapes and computer hard drives in the traditional stereos. They have continually been used in headphones and hi-fi loudspeakers to convert stored music back into sounds you can listen to.
Magnets are used in hospitals to detect problems with patient’s organs without necessarily performing any invasive surgery. This is done by a magnetic force through magnetic resonance imaging. Chemists also use magnets through nuclear magnetic resonance for characterization of synthetic compounds.
Magnetic strips are also found on automatic teller machines, debit, and credit cards. The magnetic strip is located on one side, and it contains encoded information for contacting your financial institution to connect you with your account.
Speakers and microphones also use magnets. They have a permanent magnet and a coil that carries electric current to convert the signal with electric energy to the movement, resulting in sound, which is in mechanical energy. Electric guitars are an example of an electromagnet as they use magnetic pickups to asperse the guitar strings’ vibration to electric current which is then amplified to produce sound.
You can use refrigerator magnets in adorning kitchens. They can be placed there as souvenirs or simply hold a note or a photograph to the fridge. Magnets can also be used to make jewellery such as necklaces and bracelets with a magnetic clasp. There are some which are made from a linked series of ferrous beads and magnets.
Magnets can be used in picking up and separation of magnetic items from non-magnetic ones. It can pick up objects that are too small such as staples, paper clips, iron nails, and tasks, and those that are too thin to be held by hand. They are used in salvage and scrap operations to separate magnetic from non-magnetic metals. Metals like aluminium and non-ferrous alloys don’t have any magnetic properties, and they can be often confused for magnetic metals.
You can find these metals in process industries in food manufacturing where they are used to get rid of foreign metal objects from the raw materials for processing. This helps in the detection of any problems before packaging is done, and to find any possibility of contamination.
Magnets are fascinating, and they are made to attract certain types of metal such as cobalt and nickel. The earth itself acts like a giant bar magnet, with magnetic north and magnetic south. The core of the earth is thought to be made of nickel and iron. This can be attributed to its magnetic field. Anything that creates a magnetic field or exerts a force on ferromagnetic objects are called magnets
More Fun Magnet Facts
- Playing with magnets are often the first introduction to the science that kids experience.
- The earth is magnetic due to the fact that it contains rocks such as iron that are rich in magnetic materials.
- It is also believed that the earth’s core is made of iron, which causes magnetism.
- The magnetic field of earth stretches out over the entire planet and into space. The earth’s magnetic field is called the ‘magnetosphere’ and it acts as a protection for the earth.
- Energy, including the sun’s energy, hits the earth is filled with zooming particles. When it is from the sun it is called the ‘solar wind’. When the sun’s energy hits the magnetosphere of earth and bounces off, we can see it happening in the sky with the amazing colors of the ‘auroras’.
- There are different types of ‘auroras’: the aurora borealis or ‘northern lights’ and the aurora australis or ‘southern lights’. These are all visuals of the sun bouncing off of the earth’s magnetosphere.
- The magnetic field of the earth isn’t actually that strong. It is about 1,000 times weaker than that of a magnetic bar that you might experiment with.
- The reason that we don’t fly off into space is due to gravity, not magnetism. If the earth didn’t have gravity we would be able to feel the effects of magnetism more.
- We know that other planets in the solar system have magnetic fields and some, like the moon, have little or none at all.
- Magnets have polar ends: positive and negative, also called ‘north’ and ‘south. When two of the same type are put together they ‘repel’ or push away. When two opposites (a positive and a negative) are put together, they attract each other.
- The magnetic strength of a field really depends on how close you are. The strongest magnetic areas are very close and the strength begins to weaken as you move away.
- Most metals that we are familiar with are not attracted to magnets. This can include gold, silver, aluminum, copper, magnesium and platinum.
- Magnetic fields cannot be seen with the human eye. You can do an experiment by placing metal chips that are attracted to magnets around each pole. They will align themselves up in a pattern that displays the strongest and weakest areas of the magnet.
- The measurement of a magnetic field is in units that are called ‘gauss’ and ‘Tesla’. The Tesla is named after the pioneer in electronics, Nikola Tesla.
- A magnet compass makes use of the magnetic field of the earth so that the arrow points the directions of north, south, east, west, and all of the variations of these directions.
- Scientists in the 19th century discovered that magnetism flows through electricity. Each time an electric current flows, it creates a magnetic field.
Electromagnets can be easily created by running an electric current through a surrounding coil. This is called a ‘solenoid’. They have the ability to turn the magnetic field on and off through the use of the electric current. We use electromagnets in everyday life including the door chimes at a house. The larger electromagnets are used to generate electricity at hydroelectric dams.
- The use of magnetic fields with generators and an energy source such as wind, water and steam, can create electricity.
- The magnets that you might have on your refrigerator are called ‘permanent magnets’. They hold their magnetic field full time.