Transcript Magnetic Field

Earth’s Magnetic Field
Chapter 14
Lesson 3

A magnet is any material that attracts
iron and materials that contain iron.
What is a Magnet?

Any magnet has two ends, a north and a
south pole.
◦ Magnetic poles that are alike repel each other.
◦ Magnetic poles that are unalike attract each
other.
 Remember: “Opposites Attract!”

Where is the magnetic force is the
strongest?
◦ At the poles
Magnetic Poles
The area of magnetic force around the
magnet is known as its magnetic field.
 The field lines form loops from pole to
pole, and never cross.

Magnetic Field

Use the provided magnets and ziplock bag
of iron filings to view the magnetic field.
◦ Where are most of the iron filings at?
◦ What does this tell you about the strength of
the magnet?

Test the theory of attraction and repulsion
of the North and South poles.
Magnetic Activity
Just like a bar magnet, Earth has a
magnetic field around it and two magnetic
poles.
 Compasses are devices
that have a magnetic
needle that spins freely.

Earth’s Magnetic Field

Earth has a magnetic field because of the
outer core (liquid iron) and inner core
(solid iron) moving at different speeds.
Earth’s Magnetic Field

The magnetic poles are not in the same
place as the geographic poles. The
difference (angle) between the geographic
north pole and the magnetic pole is
known as magnetic declination.
Earth’s Magnetic Field
Earth’s Protection
Earth’s Magnetic Field
Electricity and Magnetism