Download Magnets - BAschools.org

Ever see this?
Winter migration..
• Canadian geese every year travel from the north
into our region. They tend to follow predictable
routes and patterns.
• How do they find their way to where they are
going?
• As a group develop possible explanations for how
they navigate. 2 minutes
• Write down your explanation
Winter migration..
• Using your devices, books, and articles gather more
information regarding this topic.
• SSW: Based on your new information adjust your
answer accordingly.
• What did you find??
SSW
• On your notes make a list of EVERYTHING you know
about magnets/magnetism (no matter how small
or trivial).
Magnets
Day 2
Magnetism
• What makes a magnet unique?
• Objects that produce fields that attract or repel other
objects.
• What are the two ends of a magnet called?
• Poles, North (+) and South (-)
• What is attracted to a magnet?
• Opposite poles (N to S or S to N)
• Certain metals like Iron, steel, nickel, and cobalt
• What is repelled by a magnet?
• Same poles repel (N to N or S to S)
Magnetism
• What is a magnetic field?
• magnet where the force of the magnet can act.
• Can we see the magnetic field?
• Not directly
• How do we know the field exists?
• We can see how it affects other objects.
How does it work?
• Remember everything that is matter has charges in
them. However until those charges line up or move
in the same direction they have very little force.
Magnetic Force
• With the charges lined up it creates a greater
amount of force that can react at a distance.
Magnets
Day 3
Review
• What are magnets attracted to?
• What are the name of metals that are attracted to
magnets?
• What are magnets repelled by?
• What is a magnetic field?
• What gives a magnet its force?
• How do we know there is a magnetic field if we
cant see it?
• Draw a diagram of the magnetic field lines of a bar
magnet?
….we still didn’t solve yesterdays
problem……
• How do we solve which side of your round magnets
are really North or South?
Compass
•Field lines of earth’s magnetic field
come together close to the planet’s
North and South poles.
•The north-seeking pole of the freemoving magnet in the compass points
to Earth’s magnetic North Pole.
Bird Migration Video
• https://www.youtube.com/watch?v=4JUYyMHOHb
8
• https://phet.colorado.edu/en/simulation/magnetsand-electromagnets
Types of Magnets
• There are three types of magnets.
• Permanent
• Temporary
• Electromagnet
Permanent Magnets
• These are naturally occurring pieces of a mineral
called magnetite. It also has another name known
as “lodestone”.
• Key features:
•
•
•
•
Naturally occurring
Magnetic field cannot be turned off
Magnetic field has a specific direction
Must add more magnets to increase the field strength
Magnets
Day 4
Types of Magnets
• There are three types of magnets.
• Permanent
• Temporary
• Electromagnet
Permanent Magnets
• These are naturally occurring pieces of a mineral
called magnetite. It also has another name known
as “lodestone”.
• Key features:
•
•
•
•
Naturally occurring
Magnetic field cannot be turned off
Magnetic field has a specific direction
Must add more magnets to increase the field strength
Temporary Magnets
• These are pieces of iron, steel, or cobalt that have
been temporarily turned into a magnet.
• Key features:
• Occurs when a permanent magnet is rubbed along a
piece of iron, steel, or cobalt
• Magnetic field cannot be turned off, however it doesn’t
last long
• Magnetic field has a specific direction which is
determined by the permanent magnet.
• Field strength is determined by strength of permanent
magnet used on it.
What about a temporary magnet?
Electromagnet
What is electromagnetism?
• (1820) Hans Christian Oersted produced a current in
a wire during a lecture.
• When he brought a compass near the wire, the
compass changed direction.
• Whenever he turned on the current in the wire, the
compass needles lined up around the wire in the
shape of a circle.
Electric Current & Magnetism
• Wherever there is electricity, there is
magnetism
• An electric current produces a magnetic field
• This relationship is called electromagnetism
What do they look like?
• An electromagnets can be made out of a variety
of materials but they all have the following:
• Voltage source (battery or other source)
• A ferromagnetic core
• Wire wrapped around the
core. This is known as a
solenoid.
As You Enter (no notes)
1) What does ferromagnetic mean?
2) Why does a compasses north needle face the
south end of a magnet?
3) What happens inside an iron nail when you rub it
against a magnet?
4) What is electromagnetism?
Magnets
Day 5
Electric Current & Magnetism
• Wherever there is electricity, there is
magnetism
• An electric current produces a magnetic field
• This relationship is called electromagnetism
What do they look like?
• An electromagnets can be made out of a variety
of materials but they all have the following:
• Voltage source (battery or other source)
• A ferromagnetic core
• Wire wrapped around the
core. This is known as a
solenoid.
Electromagnet
• The magnetic field produced by electrical current
Key Features
• The field can be turned on and off
• The field can have its direction reversed
• The field can have its strength changed
Electromagnet
• You can turn a magnetic field produced by a
current on and off…
• How can you turn the magnetic field off?
• Simply by turning the current off!
Electromagnet
• You can change the direction of a
magnetic field…
• How can you change the direction?
• Simply by reversing the direction of the
current!
Phet
Electromagnet
•
You can increase the field of an electromagnet.
1.
2.
3.
4.
Increase the current in the solenoid
Add more loops of wire to the solenoid
Wind the coils of the solenoid closer together
Increase the strength of an electromagnet by using a
stronger ferromagnetic material for the core
Magnetic Levitation
Mag Lev
Day 6
Mag Lev
• Using the 2nd Law of Electric Charges, Like charges
repel, we can create things that float or levitate.
Mag Lev
• https://www.youtube.com/watch?v=1gMMM62NC
-4
Mag Lev
• More than just a parlor trick. Has been used to
reduce friction in trains. MagLev trains do not have
wheels, instead they have magnets that lift the
train slightly so it floats. This means less friction
which means it can go really fast (268mph).
• https://www.youtube.com/watch?v=iaElPV0FWJ0
Standing Review
• What is a magnet?
• Where is the greatest force on a
magnet?
• What is attracted to a magnet?
• What metals are ferromagnetic
metals?
• What is repelled by a magnet?
• If we cant see a magnetic field,
how do we know it exists?
• Why does the north end of
compass needle face the south
end of a magnet?
• Does a compass point to
geographic north-ish?
• Where could we find a
permanent magnet?
• Can we turn the field off on a
permanent magnet?
• What gives a magnet its field?
• Can we switch the poles on a
permanent magnet?
• What does the field around a
magnet look like?
• Can we increase the strength of a
permanent magnet?
• What is a temporary magnet?
Standing Review
• What happens inside a
temporary magnet?
• What are the parts of an
electromagnet?
• Why doesn’t a temporary
magnet stay magnetized very
long?
• How we turn the field of an
electromagnet off or on?
• Can I turn the field off and on in a
temporary magnet?
• How can I switch the poles of a
temporary magnet?
• How can we increase the
strength of a temporary magnet?
• Why does a compass line up with
a wire that has electrical current?
• What is electromagnetism?
• How can we switch the poles of
an electromagnet?
• What are the 4 ways we can
decrease the strength of an
electromagnet?
Magnets
Mixing the two…
• Lets look at what happens when we mix an
electromagnet and a permanent magnet.
Electric Motors
Electric Motor
• An electromagnet is the basis of an electric motor
• An electric motor is all about magnets and
magnetism: A motor uses magnets to create
motion.
• An electrical current running through a wire while
inside a magnetic field causes motion.
• Opposites attract and likes repel. Inside an electric
motor, these attracting and repelling forces create
rotational motion.
• A motor is consist of two magnets.
Vertical position of the loop:
Rotation
N
S
• https://www.youtube.com/watch?v=Q2mShGuG4R
Y
• https://www.youtube.com/watch?v=LAtPHANEfQo
TRANSFORMERS
Why do we need transformers?
• In most cases, machines and appliances using
electricity are manufactured to operate using a
specific voltage and frequency. However, not all
countries- and sometimes not all regions within the
same country- generate the same voltage and
frequency in their electricity.
TRANSFORMERS
• This is where transformers come in. Transformers
adjust the voltage coming into the appliance to the
proper level, and move it through the appliance to
keep it running properly.
TRANSFORMER
• A transformer can change electrical energy of a
given voltage into electrical energy at a different
voltage level. It consists of two coils arranged in
such a way that the magnetic field surrounding one
coil cuts through the other coil.
• Transformers can step up the voltage or step it
down.
• We step up voltage to send it over long distances
• We step down voltage in order to use in houses
This transformer's job is to reduce the 4160
volts down to the 240 volts that makes up
normal household electrical service. It is a
step down transformer
http://science.howstuffworks.com/power3.htm
Step Up Transformer at Power Plant
TRANSFORMER
• The factor which determines whether a
transformer is a step up( increasing the voltage) or
step down (decreasing the voltage) type is the
"turns" ratio. The turns ratio is the ratio of the
number of turns in the primary winding to the
number of turns in the secondary winding.
Step-up Transformer
http://www.ibiblio.org/kuphaldt/electricCircuits/AC/AC_9.html
• https://www.youtube.com/watch?v=ZjwzpoCiF8A
• https://www.youtube.com/watch?v=VucsoEhB0NA
EXIT TICKET
• On a piece of paper answer the following
questions:
• Why do we need transformers?
• How can you determine if it is a step up or step down
transformer?
• Why do we step up voltage?
• Why do we step down?
• https://www.youtube.com/watch?v=LAtPHANEfQo
Bird Articles
• https://www.allaboutbirds.org/the-basics-howwhy-and-where-of-bird-migration/
• http://nationalgeographic.org/media/how-dobirds-navigate/
• http://birding.about.com/od/birdbehavior/a/HowBirds-Migrate.htm
• http://www.independent.co.uk/news/science/reve
aled-secret-of-how-birds-navigate-duringmigration-818766.html
• http://www.nytimes.com/2012/04/27/science/stu
dy-sheds-light-on-how-pigeons-navigate-by-