Download Magnets and Magnetic Fields

Magnets and Magnetic Fields
Magnetic Forces
Magnetic Forces
• Is the force a magnet exerts on another
magnet, on iron or a similar metal, or
on moving charges.
- acts over a distance and varies over a
distance as well.
Magnetic Forces
• Magnetic Poles: two regions where the
magnet’s force is strongest. The one is the
North and the other is the South.
• The direction of magnetic force between
two magnets depends on how the poles
face.
• Like magnetic poles repel one another,
and opposite magnetic poles attract each
other.
Magnetic Fields
• Magnetic Field: surrounds a magnet and
can exert magnetic forces.
– A magnetic field, which is strongest near a
magnet’s poles, will either attract or repel
another magnet that enters the field.
Magnetic Field Around the Earth
• Magnetosphere: The area surrounding
earth that is influenced by this field.
– Geographic North pole is 90 degrees.
– Magnetic North pole is 81 degrees North.
Magnetic Materials
• Iron, Nickel, and Cobolt have strong magnetic
fields.
• Magnetic Domains: is a region that has a very
large number of atoms with aligned magnetic
fields.
• Ferromagnetic Material: such as iron, can be
magnetized because it contains magnetic
domains.
• When a material is magnetized, most of its
magnetic domains are aligned.
Nonmagnetized Materials
• Just because something is ferromagnetic
doesn’t mean that it is magnetized.
• If the domains of the material are not
aligned and they are randomly aligned, the
magnetic capabilities are cancelled out.
Magnetized Materials
• Some materials can become magnetized
by being placed in the magnetic field of
another magnetic, but it then loses it
magnetic capabilities. This is known as a
temporary magnet.
• When a material holds it aligned domains
for longer periods of time, it is known as a
permanent magnet.