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What is electricity?

by anj16
Tags: electricity
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anj16
#1
Feb12-12, 06:09 PM
P: 38
For a long time i thought that electricity was just electron moving in a coil from negative to positive terminals. and thats what my teachers have taught me too...
But i recently stumbled upon something called electricity through induction which has led me to doubt the above explanation.
someone please clear my doubts and please explain how electrons are transferred through air(electric induction) where positive and negative terminals cannot really be specified.
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ofirg
#2
Feb12-12, 06:32 PM
P: 90
In electrostatics, when there is no magnetic field (and therefore no induction), the electric field is conservative, and thus can be described by a potential. the current flows from high potential( positive terminal) to low potential (negative terminal), the electrons themselves flowing in the other direction ( negative charge). In induction, due the magnetic field, the electric field is no longer conservative, there is no potential for it. Therefore, for example, the current can flow repeatedly in closed wire due to induction.
cragar
#3
Feb12-12, 08:15 PM
P: 2,464
Lets say I push a metal square loop into a B field, The electrons will feel a Lorentz force
F=q(vxB) and start to move. now when each electron moves it will push the one in front of it and we will have a current.

jim hardy
#4
Feb12-12, 09:31 PM
Sci Advisor
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P: 3,515
What is electricity?

""please explain how electrons are transferred through air(electric induction) ""

they aren't transferred through air.
But while flowing along a wire they will interact with a magnet, just hook a D cell battery to a loudspeaker and watch the cone move.

When electrons move through a magnetic field they get pushed sideways.
When sideways happens to be along a wire, that's induction.
And polarity is predictable.
When sideways is perpendicular to the wire it tries to push the electrons out through the insulation so the wire feels that sideways force - that's an electric motor (of which a loudspeaker is one variety and your automobile starter is another)

Read up on "Faraday" and "Hall Effect" for starters. Use Google or Altavista search engines, there's tons of stuff on 'net at any level you want.

Have Fun ! old jim


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