New Area of Focus: Magnetism Copyright © 2010 Ryan P. Murphy.

New Area of Focus: Magnetism

Copyright © 2010 Ryan P. Murphy

Magnetism: The force produced by a magnetic field.Electric charges in motion.


A magnet is an object or a device that gives off an external magnetic field.


The term magnetism is derived from Magnesia, the name of a region in Asia Minor where lodestone, a naturally magnetic iron ore, was found in ancient times.


Visit a magnetic field simulator. http://phet.colorado.edu/en/simulation/magnets-and-electromagnets

http://phet.colorado.edu/en/simulation/magnets-and-electromagnets

http://phet.colorado.edu/en/simulation/magnets-and-electromagnets

Opposite charges attract.


The Same forces repel.


Which one is right and which is wrong?


Which one is right and which is wrong? Answer: They are both wrong.


Which one is right and which is wrong? Answer: Now they’re both right.


Activity Simulation. Magnetic Field Hockey http://phet.colorado.edu/en/simulation/elec

tric-hockey

http://phet.colorado.edu/en/simulation/electric-hockey

http://phet.colorado.edu/en/simulation/electric-hockey

Magnet: An object that is surrounded by a magnetic field and that has the property, either natural or induced, of attracting iron or steel.


After Magnetization

Electric Fields are producedby the motion of electrical charges


After Magnetization

Electric Fields are producedby the motion of electrical charges

e-Flow of negative

Electrons

Demonstration -Iron (Fe) is a very common magnet. Neodymium magnets are some of the strongest

on Earth.


Ferrofluids Video Link! (Optional) http://www.youtube.com/watch?v=kL8R8SfuXp8

&feature=related

http://www.youtube.com/watch?v=kL8R8SfuXp8&feature=related

http://www.youtube.com/watch?v=kL8R8SfuXp8&feature=related

The spinning inner cores of solid and liquid Iron creates a giant electromagnetic field.


The EM field creates a kind of force field against charged particles from hitting Earth.


This would be our Earth without the protective electromagnetic field created by our spinning core.


Activity! Drawing the earth’s EM Field.

Activity! Drawing the earth’s EM Field.

EM Field refers to Electromagnetic

Activity! Drawing the earth’s EM Field. Pass out a paper plate to everyone. Draw a Earth about the size of a golf ball in

the center. Spread iron filings all around the plate.

Activity! Drawing the earth’s EM Field. Spread iron filings all around the plate. From below, place a magnet beneath the

earth and record the magnetic field that is created.



Sketch the magnetic field / directions of the iron filings.

Activity! Drawing the earth’s EM Field. Spread iron filings all around the plate. From below, place a magnet beneath the earth

and record the magnetic field that is created. Sketch the magnetic field / directions of the iron

filings.

Activity! Drawing the earth’s EM Field. Spread iron filings all around the plate. From below, place a magnet beneath the earth

and record the magnetic field that is created. Sketch the magnetic field / directions of the

iron filings.



Sketch the magnetic field / directions of the iron filings.

Copy your sketch and label as the EM Field

Electromagnetic field protects the earth from charged particles. It also creates the Aurora borealis (Northern

Lights)

Earths EM field. Learn more: http://image.gsfc.nasa.gov/poetry/magnetism/magnetism.html

http://image.gsfc.nasa.gov/poetry/magnetism/magnetism.html

http://image.gsfc.nasa.gov/poetry/magnetism/magnetism.html

Video Link. Aurora borealis http://www.youtube.com/watch?v=FcfWsj9OnsI It needs music

http://www.youtube.com/watch?v=OPFr1nVwwsA

http://www.youtube.com/watch?v=FcfWsj9OnsI

http://www.youtube.com/watch?v=OPFr1nVwwsA

Most of the atmosphere that use to be on Mars, as well as the abundance of liquid water is now gone because of the planets weakened EM field.

Most of the atmosphere that use to be on Mars, as well as the abundance of liquid water is now gone because of the planets weakened EM field. Solar winds blew them away.

Compass: A navigational instrument for determining direction relative to the earth's magnetic poles.

The magnetic poles of the earth have shifted throughout Earth’s history.

The magnetic poles of the earth have shifted throughout Earth’s history.

Magnetism. Learn More http://www.school-for-champions.com/science/magnetism.htm

http://www.school-for-champions.com/science/magnetism.htm

http://www.school-for-champions.com/science/magnetism.htm

How to hold the compass and your posture is very important to get correct bearings.


Activity! Learning to use a compass. Put “Red Fred in the shed” Put “Black Jack in the shack”




Red Fred

Activity! Learning to use a compass. Put “Red Fred in the shed”


Red Fred

Shed

Activity! Learning to use a compass. Put “Red Fred in the shed”


Red Fred

Shed

This is the direction you walk



Shed

This is the direction you walk

Keeping Red Fred in the Shed


Shed

Follow directionArrow when Red

Fred is in the Shed


Shed


Fred is in the Shed

Not North, it will alwaysPoint north

Video Link! Using a Compass http://www.youtube.com/watch?v=6mTISEANFFY


Shed


Fred is in the Shed

Not North, it will alwaysPoint north

http://www.youtube.com/watch?v=6mTISEANFFY

Faraday's Law: The changing of a magnetic field can create voltage.


Electrical motors and generators use this law. Magnets and Electricity


Electrical motors and generators use this law. Magnets and Electricity How many products can we mention?


Activity Simulator. Faraday’s Law and introduction to electromagnets.

http://phet.colorado.edu/en/simulation/faraday



An electric motor uses the attraction and repelling properties of magnets to create motion.

Electric motors use a permanent magnet and temporary magnet.

Electric motors use a permanent magnet and temporary magnet. The permanent magnetic has a north and

south Pole.

Electric motors use a permanent magnet and temporary magnet. The permanent magnetic has a north and

south Pole. The temporary magnet is a special magnet

called an electromagnet. It is created by passing an electric current through a wire.

The motor works by passing an electric current through a wire.

The motor works by passing an electric current through a wire. The permanent magnet has a magnetic field

(north pole and south pole) all of the time.


(north pole and south pole) all of the time. The electromagnet only has a magnetic field when

current is flowing through the wire.


(north pole and south pole) all of the time. The electromagnet only has a magnetic field

when current is flowing through the wire.

The strength of the electromagnet's magnetic field can be increased by increasing the current through the wire, or by forming the wire into multiple loops.

When the battery is not connected, the temporary magnet (loop / electromagnet) sits in the magnetic field of the permanent magnet.

When the battery is not connected, the temporary magnet (loop / electromagnet) sits in the magnetic field of the permanent magnet. When you connect the battery the temporary

magnetic field interacts with the permanent magnetic field.



Attracting and repelling forces created.



Attracting and repelling forces created. These forces push the temporary magnet

(loop) which can spin freely.

Video Link and Directions. How to make a simple electric motor http://www.youtube.com/watch?v=ziWU

mIUcR2k

http://www.youtube.com/watch?v=ziWUmIUcR2k

http://www.youtube.com/watch?v=ziWUmIUcR2k

Activity! Building a small electric engine. A.) Coil the wire around the D battery

many times. Remove the coil and wrap the ends around two sides of the coil to hold it in place. Leave 4 inches of wire on each end.

Activity! Building a small electric engine. B.) Strip the TOP of both ends of the wire

coil leads.

Activity! Building a small electric engine. B.) Strip both ends of the wire coil leads.

Hold the coil vertically and coat one half of one lead with a permanent marker. Apply a second coat of ink a few minutes later.

Activity! Building a small electric engine. C.) Turn plastic cup upside down and

place magnets to the top and bottom of cup.

Activity! Building a small electric engine. D.) Straighten the outside ends of both

paper clips to form a “P.” Attach the paper clips to the cup using several rubber bands.

Activity! Building a small electric engine. E.) Balance the coil in the paper clip loop.

Adjust the height so the coil is very close to the magnets when it spins.

Activity! Building a small electric engine. F.) Attach an cable clips to each paper

clip just above the rubber band.

Activity! Building a small electric engine. G.) Connect the D-cell battery to the coil

with clips. Give the coil a gentle spin.

Activity! Building a small electric engine. H.) Make adjustments, modifications and

anything else to make it work.

Another version of the motor.

Neodymium Magnet

Okay, So how does it work? Which one is correct?

A.) The magnetic force from the battery combined with the hoop spins the ring counter clockwise.

B.) The hoop creates a Faraday cage and the extra electrons spin the hoop counter clockwise.

C.) Charges moving through a magnetic field experience a push dependent upon the direction of the magnetic field.

D.) The earth’s magnetic field is turned on when you connect the battery and spins Northward.

E.) Electrons get excited when they go around the copper wire loops. This excited state spins the loop against the electron gradient.

Okay, So how does it work? Which one is correct? And the answer is…

A.) The magnetic force from the battery combined with the hoop spins the ring counter clockwise.

B.) The hoop creates a Faraday cage and the extra electrons spin the hoop counter clockwise.

C.) Charges moving through a magnetic field experience a push dependent upon the direction of the magnetic field.

D.) The earth’s magnetic field is turned on when you connect the battery and spins Northward.

E.) Electrons get excited when they go around the copper wire loops. This excited state spins the loop against the electron gradient.

Answer: It works on the principal of Faraday's Law of electromagnetic induction. This force depends on the direction of the magnetic field. Because the wire is stripped on one side, it alternates the current from on to off every 1/2 rotation.

Halfway through the spin, the ring gets current and receives a boost.

Answer: It works on the principal of Faraday's Law of electromagnetic induction. A current-carrying conductor generates a magnetic field; when this is placed in between the poles of a strong magnet, it generates rotational motion. This force depends on the direction of the

magnetic field. Because the wire is stripped on one side, it alternates the current from on to off every 1/2 rotation. Halfway through the spin, the ring gets current and

receives a boost.

Electromagnets: By running electric current through a wire, you can create a magnetic field.


The advantage of an electromagnet is that you can turn it on and off.


We created an electromagnet when we created our electric motor.

Please record this spreadsheet.

Size of battery Number of paper clips collected

AA Trial___________ Trial___________ Trial______________

D Trial___________ Trial___________ Trial______________

Activity – Building an electromagnet Draw the finished product. How many paper clips can it pick up with AA and

then D battery? Why? Practice turning on / off with the magnet by

transporting paperclips to the empty cup.


Electromagnets. Learn more. http://www.howstuffworks.com/electromagnet.htm

http://www.howstuffworks.com/electromagnet.htm

http://www.howstuffworks.com/electromagnet.htm

Video Link! Electricity Review http://www.youtube.com/watch?v=D2mo

nVkCkX4

http://www.youtube.com/watch?v=D2monVkCkX4

http://www.youtube.com/watch?v=D2monVkCkX4

Be the first to figure out the hidden picture beneath the boxes. Raise your hand when you think you know,

you only get one guess.


Electricity and Magnetism Review Game


STUDY!

New Area of Focus: Magnetism Copyright © 2010 Ryan P. Murphy.

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Transcript of New Area of Focus: Magnetism Copyright © 2010 Ryan P. Murphy.