The document discusses magnets, their properties, and history, beginning with the discovery of natural magnets by a shepherd in ancient Greece. It outlines the types of materials that are magnetic and non-magnetic and explains how to test for magnetism, including the use of a compass and the principles of attraction and repulsion between magnets. Additionally, the document highlights various applications of magnets in everyday life and technology.

1. Fun With
Magnets
Bhavya Mohindru

2. Magnets
 A magnet is a material or object that produces a magnetic field.
 This magnetic field is invisible.
 But it is responsible for the most notable property of a magnet: a
force that pulls on other ferromagnetic materials, such as iron, and
attracts or repels other magnets.

3. Discovery
 It is said that, there was a shepherd named Magnes, who lived in ancient
Greece.
 He used to take his herd of sheep and goats to the nearby mountains for
grazing. He would take a stick with him to control his herd. The stick had a
small piece of iron attached at one end.
 One day he was surprised to find that he had to pull hard to free his stick
from a rock on the mountainside. It seemed as if the stick was being
attracted by the rock. The rock was a natural magnet and it attracted the
iron tip of the shepherd's stick. It is said that this is how natural magnets was
discovered.

4. Magnetite/ Lodestone
 In Magnesia, rocks contained large numbers of black stones which
had the power to attract peices of iron.
 The Black Stone came to be known as Lodestone or The Leading
Stone because of the way it could be used to find directions.
 Today, it is known as the mineral magnetite ( Fe3 O4 ) and is found
in many countries.

5. Magnetic & Non - Magnetic
Substances
 Materials which get attracted
towards magnets are called
Magnetic Materials, for example,
Copper, Iron, Nickle.
 Magnets can attract or repel other
magnets and can attract any
magnetic material even if it is not
magnetised.
 Non - Magnetic materials, Such as
wood, paper, plastic & most
metals, don't get attracted towards
magnets.

6. Test For Magnetism : Compass
 We can use a compass to find out wether a substance is magnetic
or not.
 One end of the compass needle normally points to north. If a
magnetic substance comes close to needle, it will make the needle
turn.

7. Test For Magnetism : Repulsion
 Take a metal & a known magnet.
 Bring one pole ( N or S ) of a magnet near the ends of the metal bar
one by one.
 If both ends of the magnet get attracted towards the metal bar, the
bar is not a magnet.
 If one end attracts and the other repels the metal bar is a magnet.

8. Magnetic Compass
 The magnetic compass functions as a pointer to "magnetic north",
the local magnetic meridian, because the magnetized needle at its
heart aligns itself with the horizontal component of the Earth's
magnetic field.
 The magnetic field exerts a torque on the needle, pulling one end or
pole of the needle approximately toward the Earth's North magnetic
pole, and pulling the other toward the South magnetic pole.
 The needle is mounted on a low-friction pivot point, in better
compasses a jewel bearing, so it can turn easily.
 When the compass is held level, the needle turns until, after a few
seconds to allow oscillations to die out, it settles into its equilibrium
orientation.

9. Attraction & Replusion
 Two magnets will be attracted by
their opposite poles, and each will
repel the like pole of the other
magnet.

10. An Isolated Magnetic Pole Does'nt
Exist
 The Magnetic Poles always exist in pairs.
 When an attempt is made to separate the magnetic poles by
breaking a magnet , the it is observed that the two parts become a
complete magnet.
 New magnetic poles are developed at broken ends.
 Thus, an isolated magnetic pole does not exist i.e each magnet is
dipole.

11. Uses Of Magnets
 It is used in a Compass to find directions
 It is used in factories for lifting heavy masses of iron.
 It is used by surgeons in hospitals to remove steel splinters from the
wounds.
 It is used in construction of telephones, electric bells etc.
 It is used to separate iron & steel from non-magnetic materials.
 And Many many more.....