Why Do We Use Magnets?
A magnet is a material or object that produces a magnetic field and attracts certain metals. The magnet was first discovered by an ancient Greek shepherd named Magnets when his stick with an iron end got stuck with a rock. We all have played with magnets in our childhood and have seen the use of magnets in many other things such as fridge magnets.
A magnet is defined as an object which is capable of producing a magnetic field and attracting unlike poles and repelling like poles.
Contents
Types of Magnets
- Permanent magnet: A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. It possesses higher retentivity and coercivity and produces a magnetic field for a longer period.
- Temporary magnet: A temporary magnet is a magnet that remains magnetized for only a small period of time. The material used to make temporary magnets is usually soft materials that have low magnetic properties such as annealed iron, steel.
- Electromagnet: Electromagnet is a type of magnet in which the magnetic field is produced by an electric current. Electromagnets usually consist of wires that create a magnetic field that is concentrated in the hole, denoting the centre of the coil. Electromagnets are much stronger as compared to a permanent and temporary magnet.
Properties of Magnets
- Attractive property: Magnets attract ferromagnetic metals like iron, cobalt and nickel.
- Repulsive property: Magnets have a north and south pole. The basic rule is that like poles repel each other whereas unlike poles attract each other. If it comes near another magnet then south and north pole will attract each other which are unlike poles but like poles north and north pole or south and south pole will repel.
- Directive property: A freely suspended magnet will always rest in the north and south direction that’s why it is used in a compass to recognise the direction.
The poles of a magnet can never be isolated. Even if we take a magnet and break it into two halves, each half will have its own north and south pole. Earth is also a giant magnet with north and south poles and a magnetic field which is called the magnetosphere.
Magnets are used in many devices. It was first used in compass for navigation purpose because a magnet always rests in a north south direction. A magnetic needle is attached in the center of the compass and it tells the direction. Magnet is also used in speakers to create vibration. Ceramic magnets are used in computer. Permanent magnets are used in refrigerator doors. It is also used in dump yard for waste management. Magnet is used to seperate metals from other waste so that it can be recycled.
Summary
Magnets have an invisible magnetic field and attract certain metals. It was first discovered by a Greek shepherd. Earth itself is a giant magnet with a north and south pole and magnetic field called the magnetosphere. There are three types of magnets permanent, temporary and electromagnets.
Magnets have certain properties – the first one is attractive property, it attracts certain metals. Second one is repulsive property – a magnet has two poles north and south. If another magnet comes near the any magnet the like poles will repel but unlike poles will attract. The third one is the directive property i.e., a freely suspended magnet will always rest in the north south direction and that is why it is used in compasses to navigate direction. If a magnet is broken into two parts both the parts will have their own poles. Magnet is also used in other devices like speakers, toys, computers, refrigerator door and motors, it is also used in dump yard to separate metals.
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