Thread: what makes the electrons move in conductor? (em induction)

What makes the electrons move in conductor, while I am moving the magnet among the conductor in closed circular loop? It is the magnetic force from the magnet, but why when I get close the magnet they start moving in direction, oppose of the magnetic force?

This one is a shot in the dark but, The electrons are repulsed by the negative magnetic pole. then they are attracted by the positive one. In an (AC) generator you have a positive pole move by and then a negative pole. Thus alternating current. So I would assume for Direct Current (DC) only one side of the magnet would move past the wires.

I do know for a fact that the magnets induce a magnetic field into the wire and the field travels at extremely high speeds something like a third of the speed of light or 10^8. The electrons themselves move far slower than almost everyone would initally guess. Its called drift velocity and its approximately 1mm/s.

Originally Posted by GenerationE

This one is a shot in the dark but, The electrons are repulsed by the negative magnetic pole. then they are attracted by the positive one. In an (AC) generator you have a positive pole move by and then a negative pole. Thus alternating current. So I would assume for Direct Current (DC) only one side of the magnet would move past the wires.

I do know for a fact that the magnets induce a magnetic field into the wire and the field travels at extremely high speeds something like a third of the speed of light or 10^8. The electrons themselves move far slower than almost everyone would initally guess. Its called drift velocity and its approximately 1mm/s.

but why they move, first opposite, thank in direction of the magnetic field?

Take a battery it has a positive and a negative terminal, at the neg terminal is a surplus of electrons whereas the positive pole has a shortage of them, attach a copper wire between the terminals and the copper wire (which has a single electron in it's outer shell easily displaced)

Now the copper has electrons easily displaced and the positive terminal has a shortage of electrons. Electrons thus begin to flow towards the positive terminal resulting in electron 'holes' drifting in the opposite direction, The reverse occurs at the negative terminal and thus current flows through the whole of the copper.

Research Electron Flow or Electron current flow for more info.

Originally Posted by Megabrain

Take a battery it has a positive and a negative terminal, at the neg terminal is a surplus of electrons whereas the positive pole has a shortage of them, attach a copper wire between the terminals and the copper wire (which has a single electron in it's outer shell easily displaced)

Now the copper has electrons easily displaced and the positive terminal has a shortage of electrons. Electrons thus begin to flow towards the positive terminal resulting in electron 'holes' drifting in the opposite direction, The reverse occurs at the negative terminal and thus current flows through the whole of the copper.

Research Electron Flow or Electron current flow for more info.

but, why they move in presence of magnetic field?

They move in the presence of a changing magnetic field but now you are down to a level where one can only truly say "We have no idea" we have some theories as to why they might but these are just theories.

Just like,

We do not know what a magnetic field is, or an electric field, or gravity. Protons, nuetrons and electrons are hypothetical particles. We do not even know what 'mass' is, what 'time' is and a whole bucket of other things, there comes a point where you accept a theory as being a 'reasonable' explanation but when you get right to the bottom of things we do not know!

Originally Posted by Megabrain

They move in the presence of a changing magnetic field but now you are down to a level where one can only truly say "We have no idea" we have some theories as to why they might but these are just theories.

Just like,

We do not know what a magnetic field is, or an electric field, or gravity. Protons, nuetrons and electrons are hypothetical particles. We do not even know what 'mass' is, what 'time' is and a whole bucket of other things, there comes a point where you accept a theory as being a 'reasonable' explanation but when you get right to the bottom of things we do not know!

So, you say tahat, there is not any theorys yet?

PLenty of theories but...


Imagine a farmer puts his sheep into a field and returns home, he gets a call to say his sheep are running around loose, he rounds them up again and checks the gate latch only to find that it is in good working order?

Those are the facts, observations, data if you like.

Our farmer formulates some theories as to why this happened.

1) He failed to close the gate properly.

2) a clever sheep opened the gate.

3) An Alien let the sheep out.

Any of these (and probably a good few more) could be the reason but of these three most people would believe the theory that the gate was not closed properly.

Thus it is with scientific theory it has to fit the facts and there has to be some supporting evidence to be credible.

In this case there is no record of 2 & 3 happening (ever) and because we know people can forget to do things properly (plus a little bit of Ockhams razor) most people would plump for theory (1). And of course he can also experiment by attempting to reproduce the conditions predicted by his theory which would clearly have the same effect in 1) whereas for theories 2 & 3 he might have a while to wait.

So yes there is a theory, but it is just that, in the same way a passing alien or intelligent sheep could have opened the gate our theory could be wrong.

because we know people can forget to do things properly (plus a little bit of Ockhams razor) most people would plump for theory three

theory 3 about aliens? i don't think the most logical explanation is that aliens let the sheep out.

Yes I seem to have transposed 1 and 3 !!! - Corrected - Well at least I know you read the post! :wink:

lol i always read what you post,

there usually correct, and quite often flame me =)

Originally Posted by Megabrain

PLenty of theories but...


Imagine a farmer puts his sheep into a field and returns home, he gets a call to say his sheep are running around loose, he rounds them up again and checks the gate latch only to find that it is in good working order?

Those are the facts, observations, data if you like.

Our farmer formulates some theories as to why this happened.

1) He failed to close the gate properly.

2) a clever sheep opened the gate.

3) An Alien let the sheep out.

Any of these (and probably a good few more) could be the reason but of these three most people would believe the theory that the gate was not closed properly.

Thus it is with scientific theory it has to fit the facts and there has to be some supporting evidence to be credible.

In this case there is no record of 2 & 3 happening (ever) and because we know people can forget to do things properly (plus a little bit of Ockhams razor) most people would plump for theory (1). And of course he can also experiment by attempting to reproduce the conditions predicted by his theory which would clearly have the same effect in 1) whereas for theories 2 & 3 he might have a while to wait.

So yes there is a theory, but it is just that, in the same way a passing alien or intelligent sheep could have opened the gate our theory could be wrong.

I understand, but do you know some of the theories which have logical sense?

You need to look up Atomic theory, copper with it's single loosely bound outer shell electron, electron and conventional current flow, and possibly other bits and pieces.

Basically

1) Electrons have a charge (negative).

2) Copper has a single electron in it's outer shell which is easily displaced (or given up to another atom)

3) A battery consists of two poles, the positive has a defficiency of electrons whereas the negative has a surplus.

4) An atom which is either difficient of ellectron(s) or has a surplus is called an ION.

You can think of this as two tall cylinders linked by a pipe with a tap, one cylinder is full of electrons when you open the tap they flow through until equalibrium is restored.

IN reality it is the electric charge which attracts the electrons,

More later...

Also look up electrolytes and electrodes. Its a couple of Ions that disolve into the battery solution or battery acid.

These two different types of solutions are kept seperate from each other in a battery. When the battery is hooked into a circuit the voltage also know as the "potential difference" causes the electrons to flow from one side of the battery to the other.

just remember opposites attract.

things with the same charge try to stay away from each other.

I have a diagram in my old physics book I could show you but I don't have a scanner.

Originally Posted by Megabrain

You need to look up Atomic theory, copper with it's single loosely bound outer shell electron, electron and conventional current flow, and possibly other bits and pieces.

Basically

1) Electrons have a charge (negative).

2) Copper has a single electron in it's outer shell which is easily displaced (or given up to another atom)

3) A battery consists of two poles, the positive has a defficiency of electrons whereas the negative has a surplus.

4) An atom which is either difficient of ellectron(s) or has a surplus is called an ION.

You can think of this as two tall cylinders linked by a pipe with a tap, one cylinder is full of electrons when you open the tap they flow through until equalibrium is restored.

IN reality it is the electric charge which attracts the electrons,

More later...

Ok, I just want to know some theories, when you will have free time, if you like, please post some of them.

Can u post the please?

Megabrain?

You will have to look on the net, under the titles I posted earlier, it would be silly for me to just copy and paste, again "Electron Theory", "Conventional Current FLow" Electron Current Flow" "Electrostatic charge" are all things that will point you in the right direction.

Originally Posted by Megabrain

You will have to look on the net, under the titles I posted earlier, it would be silly for me to just copy and paste, again "Electron Theory", "Conventional Current FLow" Electron Current Flow" "Electrostatic charge" are all things that will point you in the right direction.

I know all of that, just I don't know why the electrons move opposite of the magnetic field (when the magnet approaches), and why they move "in-line" with the magnetic field (when the magnet is going back)? Do you have any idea?

Look up Electrons in magnetic fields, but remember this is all theory, we don't actually even know if electrons exist! everything points to something behaving the way we predict electrons behaving.

Originally Posted by Megabrain

Look up Electrons in magnetic fields, but remember this is all theory, we don't actually even know if electrons exist! everything points to something behaving the way we predict electrons behaving.

please, give me some of the theories, about the behave of the electrons, while approaching or decreasing magnetic flux.