3d mag field apparatus

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Brett Waters
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3d mag field apparatus M O R E William ilbert William ilbert was born in England in 1544.

In these legends, natural rock magnets were called lodestones.

1 3d mag field apparatus M O R E William ilbert William ilbert was born in England in He was a medical doctor but became most famous for his interesting discovery about magnets. He studied many legends about magnets. In these legends, natural rock magnets were called lodestones. He studied how the earth acted like a huge, natural magnet and made lodestones work like a compass. Without a good compass, sailors sailing the seas would be lost forever! William ilbert wrote a famous book called De Magnete, which is a latin word for "on the magnet". He died in H I S T O R Y 1

orientated slightly differently seemed not to want to touch

2 The Ancient reeks noticed that sometimes certain rocks would seems to want to touch each other, and the same two rocks orientated slightly differently seemed not to want to touch With your partner come up with an explanation for this phenomena 2

3 Concept Check 3

4 Hint 4

5 5

6 More info about Faraday's accomplishments will follow 6

You need to know these Same for two souths, just arrows point the other

7 ilbert's Ideas about an invisible would revolutionize physics The following are now the accepted magnetic field drawings. You need to know these Same for two souths, just arrows point the other way Out from the North and into the South Closer the lines are together the stronger the field 7

8 CONCEPT CHECK 8

9 Oersted 9

10 Hans Christen Oersted Open Oersted Song lyrics next slide!!! Magnetism Folder Check out Attachements Hans Christian Ørsted, one of the leading scientists of the nineteenth century, played a crucial role in understanding electromagnetism. In 1820 he discovered that a compass needle deflects from magnetic north when an electric current is switched on or off in a nearby wire. This showed that electricity and magnetism were related phenomena, a finding that laid the foundation for the theory of electromagnetism and for the research that later created such technologies as radio, television and fiber optics. The unit of magnetic field strength was named the Oersted in his honor. What Oersted Noticed Convential Ørsted proved that electric current sets up a magnetic field 10

11 The Oersted Song Walter Smith & Marian McKenzie 1999 (To the tune of et out the way for Old Dan Tucker ) FYI: Worsted is a type of wool fabric. Disclaimer: We have no reason to think that Oersted was irritable, or that he wore red socks. D7 Hans Christian Oersted was a fine old Dane, C He had magnets on the brain. D7 He loved them all from pole to pole Em Cut em in half but they still were whole Refrain: D7 C So get out the way for old man Oersted D7 He s got socks of bright red worsted. 7 C Worsted s sturdy, but it sure is itchy D7 That makes old Hans Oersted bitchy. D7 Hans Christian Oersted liked to fiddle dee deedle, C Measured currents with a compass needle. D7 They named a unit for him, they say Em Fiddle dee deedling sure does pay! (Refrain) ã 2001 Walter Fox Smith 11

12 Directions of magnetic field lines. You must know how to use your hands Conventional Current Positive Charges Right Hand Electron flow negative charges Left Hand Current flowing on a wire the magnetic field is a circle around the circle Thumb is direction of charge flow Fingers curl in directin of magnetic field Check your understanding Draw direction of magnetic field in: a) Wire e b) p+ 12

Another hand rule invoves what is called a

The second hand rule helps your remember the

(a wire coiled around a core) Wrap your fingers

13 Another hand rule invoves what is called a solenoid Fonzi from happy days loved these rules The second hand rule helps your remember the behavior of a solenoid. (a wire coiled around a core) Wrap your fingers around the solenoid in the direction of charge flow through the wire. Your thumb represents the "North" direction of the induced magnetic field! Use left hand negative charges Use right hand conventional current Positive charges You try and figure out which way the charges are flowing! 13

14 Some cool symbols 14

Domain theory of Magnetism Domains not aligned Therefore the bar is not a magnet yet!

magnetic field can create magnets* Hmm isn't the earth one big magnet?

like magnetic SOUTH South pole looks like magnetic NORTH Therefore if the Earth is a magnet

15 Domain theory of Magnetism Domains not aligned Therefore the bar is not a magnet yet! After stroking it with another magnet we can line up the domains thus making the bar magnetized. Watch Mr. Fotty make a magnet This has some Interesting applications * Being in the presence of a magnetic field can create magnets* Hmm isn't the earth one big magnet? Yes the earth is magnetic in fact its magnetic field looks like the one below North pole looks like magnetic SOUTH South pole looks like magnetic NORTH Therefore if the Earth is a magnet everything that can be magnetized should be magnetized!! we do indeed find objects like skyscrapers, ships hulls becoming magnets! Concept Check: List two similarities and difference of electric and magnetic fields 15

16 Read Pages Answer Check and Reflect Section

17 Attachments bar magnet moving.mov oerstedsong.mp3

A little history. Electricity and Magnetism are related!

A little history. Electricity and Magnetism are related! Intro to Magnetism A little history Until the early 19 th century, scientists thought electricity and magnetism were unrelated In 1820, Danish science professor Hans Christian Oersted was demonstrating