CBSE Notes Class 6 Science Chapter 10 Fun with Magnets

Magnets are intriguing objects that attract materials like iron and steel through their magnetic fields. These fields arise from the movement of electric charges within the magnet, creating an invisible force. Magnets vary in shape and size, ranging from small bar magnets used in experiments to large industrial magnets employed in machinery. The basic properties of magnets are their ability to attract and repel. This means that a magnet can pull objects made of magnetic materials toward it and push them away from it. Magnets have two poles: north and south. Opposite poles attract each other, while like poles repel each other.

1.0Discovery of Magnet

In ancient Greece, a shepherd named Magnes discovered natural magnets when his iron-tipped stick stuck to a rock on the mountainside. The rock, called magnetite, attracted the iron, leading to the discovery of magnetic properties. Magnetite, named possibly after the shepherd or the place Magnesia, contains iron and was the first known natural magnet. Over time, people learned to create artificial magnets from iron, which are now used widely in various shapes like bars, horseshoes, and cylinders.

2.0Magnetic and Non Magnetic Materials

Magnetic Materials: These are attracted to magnets. Common examples include:

• Iron
• Nickel
• Cobalt

Non-Magnetic Materials: These are not attracted to magnets. Examples include:

• Plastic
• Wood
• Glass
• Soil

3.0Poles of Magnet

1. North Pole: This is the end of the magnet that points towards the Earth's north when freely suspended. It is labeled as the north-seeking pole.
2. South Pole: This is the end of the magnet that points towards the Earth's south when freely suspended. It is labeled as the south-seeking pole.

• Magnets have two poles: north and south.
• Unlike poles attract each other (north attracts south).
• Like poles repel each other (north repels north and south repels south).

4.0Finding Direction From Magnet

1. Suspend the Magnet: Hang the bar magnet on a thread or pivot so it can rotate freely.
2. Observe Alignment: When the magnet settles, one end will point north and the other south.
3. Identify Poles:

• The end pointing north is the North Pole of the magnet.
• The end pointing south is the South Pole of the magnet.
•  The magnet aligns with the Earth's magnetic field, with its north-seeking end pointing towards the Earth's magnetic north and the south-seeking end towards the Earth's magnetic south.

5.0Magnetic Attraction and Repulsion

• Magnetic Attraction: Occurs when opposite poles of magnets (north and south) come close and pull towards each other.
• Magnetic Repulsion: Happens when like poles (north-north or south-south) are brought close and push away from each other.
• Unlike poles attracts .
• Like poles repel.

6.0How Magnets Lose Their Magnetism

• Excessive heat can cause loss of magnetism
•  Dropping or hitting a magnet can weaken its magnetic properties.
•  Over time, magnets can lose strength, particularly under harsh conditions.