Lenz and Faraday

Michael Faraday b. Sept. 22, 1791, Newington, Surrey, Eng. d. Aug. 25, 1867, Hampton Court
Faraday announcing his discovery to his wife on Christmas morning, 1821 He was the first to produce an electric current from a magnetic field
He discovered that when a permanent magnet was moved in and out of a coil of wire a current was induced in the coil.!!
http://micro.magnet.fsu.edu/electromag/java/faraday2/
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Essentially this was his idea
By moving the rod in a magnetic field we can motivate the the charge (electrons or protons) to move in the wire thus creating a current and voltage!
This is called an induced current
Play UTOPIA
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Hmm If current makes magents could magnets make current?
This was the work and discussion, of two main physcists Faraday and Lenz (Play the song)
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FARADAY
A Physics Utopia
Words & music by Walter Smith 2­01
Chords by Marian McKenzie 3­27­01
G C F C G
Together let’s build a new nation
F C G7
That’s founded on truth and on love­­
G C F C (G)
No war, no disease, no privation,
F G7 C
Our senators blessed from above.
F C
But what in this country so gleaming
G7 C
Shall our guiding principle be?
F Em
O what song from our lips shall be streaming
D G
As we march so victoriously?
G7
Why ­­
C F C G
Faraday’s law of induction
F C G7
The law of all sea and all land­­
G C F C (G)
No lies, no deceit, no corruption
F G7 C
In this law so complete and so grand!
F C
Our children will sing it in chorus –
G7 C
“Circulation of vector cap E,”
F Em
Yes they’ll sing as they march on before us,
D G
“Equals negative d by dt
G7
Of ­­
C F C G
Magnetic flux through a surface,”
F C G7
They’ll conclude as we strike up the band.
G C F C (G)
We’ll mark all our coins with our purpose ­­
F G7 C
“On Maxwell’s equations we stand!”
F C
It’s Faraday’s law of induction
G7 C
That allows us to generate pow’r.
F Em
It gives voltage increase or reduction ­­
D G
We could sing on and on for an hour
G7
About ­­
C F C G
Faraday’s law of induction
F C G7
The law of all sea and all land­­
G C F C (G)
No lies, no deceit, no corruption
F G7 C
In this law so complete and so grand!
ã 2001 Walter Fox Smith
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NASA was the first to actually really apply this idea
The space station is made of metal, this metal is under the influence of the earth's magnetic field
simply by having the station move aorund earth's magnetic field creates electrictiy for the station
Applications to airplaines on earth also!
The wings of an airplane have grounding material so that
there would be no electrical interactions with the planes equipment
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Some interesting notes about this induced current.
1. Magnets make current
but
2. Current in turn makes magnets
A fellow by the name of Lenz is responsible for this discovery. His classic experiment his outlined in this video clip
Heinrich Friedrich Emil Lenz b. February 12,1804, Dorpat, Russian Empire (now Tartu, Estonia) d. February 10, 1865, Rome, Italy
Lenz explained this effect by saying the following
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Thus the induced current will generate a magnetic field, and it is possible to predict the direction of the magnetic fields using our left hand!
The induced magnetic field always resists the magent being inserted !! Lenz's Law
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This is where we need monkeys on speed!
Check and Reflect 12.4
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Attachments
http://online.cctt.org/physicslab/content/applets/JavaPhysMath/java/partmagn/index.html
lenzs law.wmv
utopia.mp3