Download What is a Magenit? - Spring Branch ISD

What Is a Magnet?
• There are several different types of a
magnets, some are natural of others are man
made
• Magnets found in nature were first called load
stones and were used as compass, many
natural magnets are made up of iron, nickel,
and cobalt
• Magnets can also be man made by using
electricity, these magnets are called
electromagnets
Parts of a Magnet
• All magnets have two parts
– North-seeking pole (north pole)
– South-seeking pole (south pole)
• Magnetism were first used as compasses
because one end always moves to point
north, while the other end moved to point
south
• Because every magnet has these two poles
magnets are called DIPOLE
(Di = two, poles=poles)
• Even if a magnet is broken in two or
more pieces each piece will have two
poles
How Magnets Work
• Every magnets works by generating what is
called a MAGNETIC FIELD.
• This field is how a magnets created of
magnetic force. When the field reaches an
object made with iron, nickel, or cobalt it
creates a magnetic force pulling the metal to
the magnet.
• If the field from the one pole of a magnetic
meets with the field from an opposite pole of
a magnet the poles attract.
• If the field from the one pole of a magnetic
meets with the field from a same pole of a
magnet the poles repeal.
• Opposites attract, likes repeal.
What the Magnetic Field Looks Like?
S
N
Two Poles means a Dipole, all magnets are dipoles
The Field Between Two Poles
S
S
N
S
N
N
What Makes a Magnetic Field?
• Magnetic fields are made when charges
(protons, electrons) move.
• Magnetism means motion, charges have
to move to create a magnetic field and
force.
What Makes a Magnetic Field Cont.
• All materials are made
up of atoms.
• In these atoms
electrons move around
the nuclei of the atoms.
– It is this motion that
creates small
magnetic fields.
• Everything that is made
up of atoms creates
small magnetic fields.
Making a Magnet Takes Organization.
• Every atom makes
Non-magnet
it’s own magnetic
field.
• For non-magnets
these fields points in
Magnet
all directions,
canceling each other
out so that there is
not net field.
• In magnets most of
Magnetic Domains are
these fields point in
clusters of atoms the have their
the same direction,
magnetic field pointing in the same creating a strong net
direction
magnetic field.
Electrical Currents and Magnetic
Fields
• Magnetic fields are made when charges
move.
• Electrical current is the movement of
charges.
• Therefore magnetic fields are made by
electrical current.
– The more current you have, the stronger
the magnetic field is.
What the Field Looks Like for a Wire
With Current.
• The magnetic field wraps around a wire that has an
electrical current moving through it
If the wire is wrapped in many loops strong electromagnets
can be made.
Magnetic Forces on a Wire
Magnetic force
Magnetic Field
Current
The Right Hand Rule
Fingers = field
Palm = Force
Thumb = current
Memory trick:
The field has many lines, like you have many fingers
You get slapped (feel a force) which the palm of the hand
If a person needs to go we use the thumb