Fun With Magnets Class 6 Notes CBSE Science Chapter 13 (Free PDF Download)

Magnet:

• Magnets are compounds that have the ability to attract materials such as iron, cobalt, and nickel.

• Magnes, an ancient Greek shepherd, was the first to discover a magnet.

• There are two types of magnet, as

1. Natural Magnet :

• The magnet that is found in nature is a Natural Magnet.

• Magnetite, Lodestone are examples of Natural Magnets.

2. Artificial Magnet : 

• Artificial magnets are created by humans.

Magnetic Force:

1. The magnetic force is the force that a magnet uses to attract an object to itself.

2. When two magnets are close enough to touch or come into contact, they exert a force on each other, similar to how electrical charges do. The magnetic force is this force.

Poles of a Magnet:

1. Magnetic materials (such as iron filings) do not adhere equally to all areas of a magnet when brought close to it. They stick to certain areas of the magnet more than others. These are known as the magnet's poles. 

2. At the poles, magnetic forces are the strongest.

3. Every magnet is bipolar, which means it has two poles at the ends.

4. The North and South poles are the two poles of a magnet.

• North Pole:

The north-seeking end, often known as the North Pole, is the end that points northward.

• South Pole:

The end pointing south is known as the South Pole or the south seeking.

• The N-S axis of a freely hanging magnet is always aligned.

• Poles that are similar repel each other, while poles that are dissimilar attract each other.

• Magnetic poles are always found in groups of two.

• A bar magnet is divided into four poles when split in half, with a North and South Pole on each side.

Different Types and Shapes of Magnets:

Magnets are categorised into numerous categories based on their shapes, these are listed as below;

1. Bar magnet

2. Ball-ended magnet ( Dumb-bell )

3. Horseshoe magnet

4. Cylindrical magnet

5. Magnetic needle

6. Artificial magnet

7. Loadstone ( natural magnet)

8. Ring or disc shape magnet

Temporary Magnets:

• Temporary magnets are magnets that are only used for a limited period of time.

• Iron bar magnets are used as temporary magnets.

Permanent Magnets:

• Permanent magnets have a long lifespan. 

• They're made of steel or an AlNiCo alloy, which combines aluminium, nickel, and cobalt.

Classification of Substances Based on Attraction to Magnets:

• Magnetic Substances: Magnets are compounds that have the ability to attract materials such as iron, cobalt, and nickel, etc.

• Non-Magnetic Substances: Nonmagnetic materials include plastic, wood, paper, rubber, most metals and other materials that are not attracted to a magnet.

Methods to Make Your Own Magnet:

1. Single Touch Method: The iron object becomes magnetised when a magnet is used to massage it along its length from one end to the other, similar to combing one's hair.

2. Double Touch Method: The bar or the object becomes a magnet when it is rubbed by two powerful bar magnets of equal strength with their opposite poles at the centre, in opposite directions.

3. Using Electric Current: The magnetic bar is inserted inside a conductor's coils, and current is passed via the wire coils.

Properties of Magnet:

1. The North Pole and the South Pole are the two poles of a magnet.

2. Poles that are similar repel one other.

3. Opposing poles are attracted to one another.

4. Magnetic poles are always found in groups of two.

5. There is no magnet that compares to a monopolar magnet. When it comes to magnets, they are always bipolar.

Applications of Magnet:

• Compass Needle: The compass consists of a small glass container with a magnetised needle pivoting on an aluminium nail. The needle is unrestricted in its rotation. Because the earth is also a gigantic magnet, it points north-south. The magnetic field of the earth is aligned with the compass.

• In factories, it's used to move massive amounts of iron, such as scrap iron.

• An electromagnet is used in doorbells and chimes.

• Permanent magnets in loudspeakers are used by surgeons in hospitals to remove steel splinters from wounds.

• Used to separate iron and steel from non-magnetic materials in the building of telephones, electric bells, and other devices.

• A strip of magnetic material on credit cards, ATM cards, and identity cards retain information.

• Magnets are used in television and computer monitors.

• Magnetic material is used to store information on computer hard discs, as well as audio and video cassettes.

• In the scrapyard, magnets are used to pick up iron-based materials.

Demagnetisation, (Loss of Magnetic Property of a Magnet):

• When a magnet is hammered, heated, improperly stored, or dumped with force and strikes against a hard substance, it loses its magnetic property.

• Each pole will destroy the other by induction if two bar magnets are not stored with their similar poles pointing in the same direction.

• Dropping from a height dissimilar poles alongside each other is the best way to store bar magnets in pairs. 

• A piece of soft iron should be placed across the poles of a horseshoe magnet when storing it.

Taking Care of Magnets:

• Magnets should be stored in non-magnetic materials such as cardboard or wood when not in use. 

• Keepers must be used to safeguard magnets.