Science is everywhere around us and understanding it makes our life much easier and fascinating too. Kids love to play with magnets and playing with magnets give initial lessons of science to them. Imagine how fascinating would it be for kids to see magnets attracting their toy cars, paperclips, cells, cans etc. So exactly what is a magnet.
A magnet is something that attracts certain metals like iron, nickel, cobalt. It has invisible force that pulls certain metals. This force is called MAGNETISM. A lodestone is a natural magnet.
Magnets that we see in the market come in different shapes like bar magnet, horseshoe magnet, flat circular disc-shaped etc but common feature of all is that all magnets have two ends called poles. One is NORTH POLE and other SOUTH POLE.
When we hold two magnets together, they either ATTRACT (pull) or REPEL (push away). To understand this, let us know more about magnetism.
Every magnet has a magnetic field around it which is the invisible lines of magnetic force which leave magnet from its north pole and re enters the magnet at its south pole. We can call it, invisible area of magnetism .
On bringing two magnets closer, the north pole of one magnet will attract south pole of other magnet and vice versa but two north poles and two south poles will always repel.
So, we learn that LIKE POLES REPEL AND UNLIKE POLES ATTRACT.
A very significant feature of magnet is that its magnetic field is stronger at the poles than in the center. We can see this by immersing magnet in iron fillings, almost all the pins will stick at the two ends of a magnet which shows that magnet is stronger at its poles or ends.
Magnets can be temporary or permanent. The magnets that we get in the market are permanent ones. These donot lose their magnetic properties. Temporary magnets behave like magnet only if they are in contact with permanent magnet.
e.g. if a magnet is brought near iron nail, it will stick to magnet and behave like a magnet. It will now attract another nail which will stick to first nail and likewise a chain is formed as all nails will start behaving like a magnet but once the permanent magnet is removed, they will become ordinary nails.
A bar magnet if suspended freely in air will always allign itself in a particular direction. The North pole of a magnet points towards earth's geographical North and South pole of a magnet points towards earth's geographical South. This property is used in making Compass.
A Compass is made of tiny magnet in shape of needle which can spin. The North pole of compass needle will always point towards earth's geographical North pole. So it helped sailors find their way in the sea.
It is of great interest to know that our Earth behaves like a giant magnet. The core of the earth has molten rocks rich in iron responsible for this magnetic behaviour. This is the reason why a freely suspended magnet always align along the geographical N-S direction.
USES OF MAGNETS
1. Magnets are used to seperate magnetic substances from a mixture.
2. The doors of refrigerator has a weak magnetic strip to help keep the door closed firmly. The doors of the cupboards have magnetic latches for the same purpose.
3. Magnets are used in microwaves, loud speakers, motors, generators etc.
4. Magnets find their use in computer hard disk, floppies, audio and video tapes.
5. Magnetic stripes on credit cards, ATM cards, airline tickets is used to store information.
IMPORTANT FACTS
1. Earth has magnetic field which stretch out into space and can affect things around.
2. Sun has magnetic field several times stronger than earth.
3. Moon has little or no magnetism.
4. Other planets like Saturn, Jupiter, Neptune and Uranus have stronger magnetic field than Earth while Mars, Mercury and Venus has weaker field.
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| Lodestone |
Magnets that we see in the market come in different shapes like bar magnet, horseshoe magnet, flat circular disc-shaped etc but common feature of all is that all magnets have two ends called poles. One is NORTH POLE and other SOUTH POLE.
When we hold two magnets together, they either ATTRACT (pull) or REPEL (push away). To understand this, let us know more about magnetism.
Every magnet has a magnetic field around it which is the invisible lines of magnetic force which leave magnet from its north pole and re enters the magnet at its south pole. We can call it, invisible area of magnetism .
On bringing two magnets closer, the north pole of one magnet will attract south pole of other magnet and vice versa but two north poles and two south poles will always repel.
So, we learn that LIKE POLES REPEL AND UNLIKE POLES ATTRACT.
A very significant feature of magnet is that its magnetic field is stronger at the poles than in the center. We can see this by immersing magnet in iron fillings, almost all the pins will stick at the two ends of a magnet which shows that magnet is stronger at its poles or ends.
Magnets can be temporary or permanent. The magnets that we get in the market are permanent ones. These donot lose their magnetic properties. Temporary magnets behave like magnet only if they are in contact with permanent magnet.
e.g. if a magnet is brought near iron nail, it will stick to magnet and behave like a magnet. It will now attract another nail which will stick to first nail and likewise a chain is formed as all nails will start behaving like a magnet but once the permanent magnet is removed, they will become ordinary nails.
A Compass is made of tiny magnet in shape of needle which can spin. The North pole of compass needle will always point towards earth's geographical North pole. So it helped sailors find their way in the sea.
It is of great interest to know that our Earth behaves like a giant magnet. The core of the earth has molten rocks rich in iron responsible for this magnetic behaviour. This is the reason why a freely suspended magnet always align along the geographical N-S direction.
USES OF MAGNETS
1. Magnets are used to seperate magnetic substances from a mixture.
2. The doors of refrigerator has a weak magnetic strip to help keep the door closed firmly. The doors of the cupboards have magnetic latches for the same purpose.
3. Magnets are used in microwaves, loud speakers, motors, generators etc.
4. Magnets find their use in computer hard disk, floppies, audio and video tapes.
5. Magnetic stripes on credit cards, ATM cards, airline tickets is used to store information.
IMPORTANT FACTS
1. Earth has magnetic field which stretch out into space and can affect things around.
2. Sun has magnetic field several times stronger than earth.
3. Moon has little or no magnetism.
4. Other planets like Saturn, Jupiter, Neptune and Uranus have stronger magnetic field than Earth while Mars, Mercury and Venus has weaker field.
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