Introduction to magnetism and its effects

2. An area around a magnet in which a
ferromagnetic substance will experience
a force
• Electrons in atoms are constantly moving
around the nucleus of the atom
• Moving charges cause a magnetic filed that is
perpendicular to the direction of motion
• Indicated by magnetic field lines

3. • Atoms with magnetic fields in the same direction collect
in the same regions
• Are called magnetic domains
• When ferromagnetic substances enter a magnetic field,
the domains align themselves with the magnetic field of
the magnet
• In non-magnetic substances, atoms are arranged
randomly
• Magnetic fields cancel each other out

4. • Has a North pole and a South pole
• Direction of magnetic field: North to South
• Magnetic field lines do not cross
• Magnetic field lines do not touch
• Density of fileldlines indicate strength of the
magnetic filed

5. Opposite poles attract each other

6. Like poles repel each other
X
Geen Magneetveld

8. • Geographic poles: Determined by
geographic position as the areas that do not
experience sunsets
• Magnetic Poles:
• Determined by earths magnetic field
• Deviate from geographic poles – magnetic
declination
• Magnetic north is classified as the pole to
which the north pole of a bar magnet will
point
• Is therefore actually a south pole

9. • Sun emits charged particles
toward the earth – is called sun
wind
• Sun wind is dangerous for life
and can damage infrastructure
on earth
• Earth’s magnetic field deflects
most of the particles away from
the earth
• Protects the earth against sun
wind

10. • Particles from sun wind that
enter earths magnetic filed
collects at the poles where
magnetic field is the strongest
• Particles collide with gas
molecules in earths
atmosphere
• Ionises these molecules
• Molecules emit this energy in
the form of light and cause the
Aurorae