MAGNETISM

Magnetism is a material in the form of black stone that could attract metallic such as of iron and steel .

What is the magnetism?

MAGNETIC MATERIALS

Magnetic materials can be classified into 3 categories:a. Ferromagnetic, materials that can be strongly attracted by a magnet.b. Paramagnetic, materials that can be weakly attracted by magnetc. c. Diamagnetic, materials that can not be attracted by magnet

Ferromagnetic

(Iron)(steel)

(Nickel)

PARAMAGNETIC

(platinum) (aluminum)

(wood)

(mercury) (gold)

DIAMAGNETIC

The properties of magnet :

North pole

South pole

A freely suspended magnet always come to rest Pointing in the North-south direction

. Magnet has two poles, the north pole and south pole

Poles of the magnet is the ends of the magnet are very strongly attracting

Interaction between the poles of magnet can be states as:

Unlike poles attract (pull) each other

Like poles repel (push) each other

Theory of magnetism

N

Magnet do not lose their magnetism even if they are cut into pieces

The difference between magnetic and non magnetic

The magnetic properties of a material will appear if its particles (dipoles) are lined up in the same direction.

otherwise, if the dipoles are pointing in random direction

Magnetic steel

Non magnetic steel

THE METHODS TO MAKE A MAGNET

A bar of iron or steel that is nonmagnetic can be made A magnet by being rubbed with a permanent magnet in one Direction repeatedly

A permanent magnet the magnetic property of which is Strong can make a ferromagnetic material that is not magnetBecome a magnet when it is brought close to.

( Iron rod)

Rubbing method

Induction method

(((nail)

THE METHODS TO MAKE A MAGNET

Conducting electric current method ( Electromagnetic)

A piece metal , such as iron can be made a magnet by winding a conductor wire on the metalThen it is conducted by electric current (battery)

THE DIRECTION OF ELECTROMAGNETIC FIELDS

I = the direction of electric currentB= the direction of mgnetic fildA = the direction of force

A B

What poles are they?

ELECTROMAGNETIC USES

Electric Bell

An electric bell also work using electomagnets.-These electromagnets consist of soft iron Cylinders . Wire is wound around the cylinders One end of the wire is connected to a battery, the other to a spring.

-When the battery is connected, the current flows through a contact to the spring, passing through the coil and goes back to the battery. When the current passes the coil, the iron core of the cylinders will become a magnet. This iron core will pull striker, causing the striker the bell and there is sound. Many times.

coil

Soft Iron

Galvanometer

A multimeter is usully used to mesure current, voltage, An resistance.

MAGNETIC FIELD

Magnetic field is the area around a magnet where the magnetic force works

What do you know, if two magnet poles the closed to each other?How can you shows force lines between two bar magnets above?

EARTH HAS MAGNETISM

Why does a pole of a bar magnet that is hung on a thread always point to the north And the other to the south?

The north pole of Earth magnet lies on the south pole of Earth and the south pole of Earth magnet lies on the north pole of Earth.