Magnetic Field

Magnetic Field - 2) Geographic North pole is actually a...

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Magnetic Field – seems like giant bar magnet at center of Earth Why? Dynamo Effect – spinning outer core acts like giant electrical generator - Electrons moving in convection cycles create circular current - Circular current creates giant dipolar (North/South poles) magnetic field 1) When charged particles move quickly, it creates a magnetic field 2) Electrons can move freely in conducting liquids, such as molten material in outer core 3) When many charge particles move together, producing macroscopic magnetic field Oddities of Earth’s Magnetic Field 1) Magnetic poles offset from rotational axis poles (North/South) by ~12°
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Unformatted text preview: 2) Geographic North pole is actually a magnetic South Pole (vice versa) 3) Magnetic field reverses polarity approximately every average 250,000 years (last reversal ~780,000) 4) Magnetic field produces magnetosphere protective layer around Earth that stops charged particles from entering 5) Magnetosphere produces Van Allen Belts belts/donuts of trapped particles inside magnetosphere 6) Solar wind produces aurora charged particles enter magnetosphere at poles and interacting with atmosphere glow...
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This note was uploaded on 02/17/2010 for the course PHY 115 taught by Professor Weinbeck during the Spring '09 term at BC.

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Magnetic Field - 2) Geographic North pole is actually a...

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