Chapter 16: Magnetism P Physics Objectives: 1.Describe the behavior of magnets. 2.Inside a magnet. 3.The magnetic field. 4.The link between magnetism and electricity. 5.The electromagnet

Objective: -What is a magnet? Key words: alloy 1-Three metallic elements show strong magnetic properties: Iron Fe, Cobalt Co, and Nickel Ni. 2-Steel is a metal alloy that can show magnetic properties, it is made from Iron Fe and Carbon C. -Steel is mixed with other metals to make an alloy which doesn’t show magnetic properties like Stainless Steel (Steel+ chromium + nickel).

A magnet 3- A magnet is a material that is showing magnetic properties and it is said to be magnetized.

Objective: -Describe the behavior of a magnet Key words: attract, repel The behavior of magnets: 1-Magnets: 1-Magnets: * Can attract or repel other magnets and can attract any magnetic material even if it is not magnetized *When suspended from a thread, a bar magnets aligns itself in a north south direction.

2-Non magnetic materials: 2-Non magnetic materials: like wood, paper, plastic and most metals. *Can not be magnetized. *Some such paper and water can let the force of magnetism pass through them

Objective: -Describe the strength of the magnetic force Key words: magnetic force, pole, magnetic induction The strength of the magnetic force: - At each end of a bar magnet is a place where the magnetic force is stronger than at other places in the magnet ; they are called poles of the magnet, North pole + South pole Different poles attract, Similar poles repel.

Objective: -Describe the strength of the magnetic force Key words: magnetic force, pole, magnetic induction The strength of the magnetic force: magnetic induction - When a material that can show magnetic properties is attracted to the end of a magnet it becomes also a magnet and can attract other magnetic materials to it, but when it is moved away from the magnet it loses its magnetism. This process is called magnetic induction

Objective: -Describe particles inside a magnet Key words: Domain, hard magnet, soft magnet Inside a magnet: -Groups of particles from which a magnetic material is made from tiny regions called domains. -once domains are arranged in lines they the material change into magnet.

Objective: -Describe particles inside a magnet Key words: Domain, hard magnet, soft magnet Inside a magnet:

Objective: -Describe the magnetic fields Key words: magnetic fields The magnetic field: -The region around a magnet in which the pull of the magnetic force acts on magnetic materials is called the magnetic field.

Objective: -Describe the Earth’s magnetic fields Key words: magnetic fields The Earth’s magnetic field; -At the center of the earth is the earth’s core : is made of iron and nickel and it is divided into two parts(1-the inner core made of solid metal and 2-the outer core made liquid metal )

Objective: -Describe the Earth’s magnetic fields Key words: magnetic fields The Earth’s magnetic field; -As the earth spins, the two parts of the core move at different speeds and this is thought to generate the magnetic field around the earth and make the earth seem to have a large bar magnet inside it.

Objective: -Describe the Earth’s magnetic fields Key words: magnetic fields The Earth’s magnetic field; -The earth spins on it axis which is an imaginary line that runs through the center. The ends of the line are called geographic north and south poles.

-Geographic & Magnetic Poles Earth’s geographic North Pole is actually a south magnetic pole Earth’s geographic North Pole is actually a south magnetic pole A compass needle’s “north” end is actually attracted to Earth’s “south” magnetic pole!

discover the link between magnetism and electricity Objective: - discover the link between magnetism and electricity The link between magnetism and electricity: Key words: The link between magnetism and electricity: