Magnet: Definition, Properties, Types, Characteristics & Uses
A magnet is a material that produces a magnetic field, which is able to attract opposite poles i.e. north and south pole and repel similar poles i.e. north-north pole and south-south poles. Magnets were discovered almost 4000 years ago by a Greek shepherd named Magnes. The first magnet was found in a naturally occurring mineral known as magnetite.
Continue reading to study about magnets, their properties, types, characteristics and applications.
Magnet
Magnets are materials that produce a magnetic field, which is able to attract opposite poles i.e. north and south pole and repel similar poles i.e. north-north pole and south-south poles.
Above shown is an image of a bar magnet surrounded by iron fillings. The red part represents the north pole, denoted by N and the blue part represents the south pole represented by S.
Magnets are available in various shapes such as bar magnets, circular magnets, horse-shoe magnets, etc.
Properties of Magnet
Let us study some properties of magnets:
- Attractive Property: The most basic property of a magnet is that it tends to attract ferromagnetic materials such as iron and nickel.
- Repulsive property: Magnets repel similar poles.
- Directive property: The tendency of a magnet to align itself when suspended in air is known as its directive property.
- Law of magnetic poles: According to the law of magnetic poles, like poles repel each other and opposite poles attract each other.
- Pair property: If you take a magnet and cut it into two halves, the newly formed magnets will also have north and south poles, similar to the parent magnet.
Types of Magnet
Magnets are of three types: Permanent magnets, temporary magnets & electromagnets.
Permanent magnet: A magnet that retains its magnetic properties even in the absence of a magnetic field is known as a permanent magnet. But in some rare cases where the temperature is very high, in case of stressful conditions, even permanent magnets can lose their magnetic properties like magnetic flux.
What are the ways to demagnetize permanent magnets?
When kept in extreme temperatures, permanent magnets demagnetize
Hammering the magnet loosens the magnetic attraction between atoms, resulting in demagnetization.
Temporary magnet: Magnets that are formed when ferromagnetic material is brought under the influence of a strong magnetic field are known as temporary magnets. They are also known as soft magnets because they are made up of soft materials such as iron alloys etc.
Electromagnets: Electromagnets are made by wrapping coils of wire around an iron core. After the iron core is wrapped up, electricity is passed through the wires, the whole set-up i.e electromagnetic device behaves like a magnet. When the current supply is turned off, the magnetism of the set-up also goes away.
Characteristics of Magnet
The characteristics of magnets are as follows:
- A magnet has two poles, the north and south pole.
- Magnets possess the property of attraction and repulsion. It attracts opposite poles like north and south but repels the same poles such as north-north and south-south poles.
- Magnetic poles exist in pairs.
- Magnetic lines of force acting between two poles is directly proportional to the distance between them i.e. the lesser the distance, the more is the force of attraction and vice versa.
- Some magnets can be demagnetized (permanent magnets).
In some materials magnetism can be induced by using electric current.
Uses of Magnet
Since we have discussed about magnets, let us study about some of the uses of magnets:
- Magnets are used in speakers.
- Magnets can be found in electric bells, electric cranes, etc.
- In day-to-day life, magnets can be found in television, cars, computers, motors, etc.
- Temporary magnets find application in the manufacturing of electromagnets.
- They are found in the mariner’s compass.
- They are used for making magnetic needles and compasses.
We hope the concept of magnet was interesting to read and study. You can also check out more interesting Physics topics. You will find more such things on the Testbook App. Prep for your Exams in a fun, interactive manner, with mock tests curated by experts in the field as well as exclusive study material available at your fingertips. Get the app and get working!