Explain to me Electromagnetic Induction, EMF to be exact...

[QueenZ]

sadly i culd give you an indepth explanation but i fear we will only go off on a tangent and il spend half the night on this thread lol

I have already looked into the quantum world, quantum entanglement etc. so go ahead...

 

[telectrix]

time for bed. said zebedee.

 

[Darkwood]

Already read it....

Well it was your opening post that suggested you hadn't read with the mention of electrons moving, but it should give you insight, il try explain it in everyday terms, you have 2 magnets one in each hand and you sweep the magnets passed each other close together and you will feel the force between them, its similar force thats acting on a quantum level to the electron field, if the magnet stayed still the electron field would just re-organise but by moving the magnet it can create a wave effect to the field.
If you want to understand again in everyday terms what happens with electrons and how the field moves then the best way to explain something like current in a.c. would be a straw full of a million electrons end to end all in a single file, (small straw) if you have a potential difference between the ends of the straw then the eletrons will want to go to the positive end so push 1 electron in the negative end at at the same instance the electron at the other end will fall out, as its ac the field reverses so the electron thats just fallen out gets push back in and instantly the original electron you pushed in drops back out.
Now the action of pushing the electron in and the electron at the far end was instant (electromagnetic field) but each electron has only moved back and forth and kept its position more or less.
In d.c. you keep pushing them in one end only so the propogation is the same (near light speed) but the electrons migrate slowly to positive in the order of mm per hour.


Hope this helps

 

[QueenZ]

time for bed. said zebedee.

you're right... :aureola:

 

[QueenZ]

Well it was your opening post that suggested you hadn't read with the mention of electrons moving, but it should give you insight, il try explain it in everyday terms, you have 2 magnets one in each hand and you sweep the magnets passed each other close together and you will feel the force between them, its similar force thats acting on a quantum level to the electron field, if the magnet stayed still the electron field would just re-organise but by moving the magnet it can create a wave effect to the field.
If you want to understand again in everyday terms what happens with electrons and how the field moves then the best way to explain something like current in a.c. would be a straw full of a million electrons end to end all in a single file, (small straw) if you have a potential difference between the ends of the straw then the eletrons will want to go to the positive end so push 1 electron in the negative end at at the same instance the electron at the other end will fall out, as its ac the field reverses so the electron thats just fallen out gets push back in and instantly the original electron you pushed in drops back out.
Now the action of pushing the electron in and the electron at the far end was instant (electromagnetic field) but each electron has only moved back and forth and kept its position more or less.
In d.c. you keep pushing them in one end only so the propogation is the same (near light speed) but the electrons migrate slowly to positive in the order of mm per hour.


Hope this helps

I'll read it a couple of times and try to get it...

 

[Knobhead]

How come this thread has got dumped in this section? It's got nothing to do with commercial/industrial at all.

 

[plugsandsparks]

Dunno, isn't there a GCSE physics forum somewhere this can go cos its doing my head in.

 

[Knobhead]

Pity there isn’t a skip section it could be dumped in!

 

[Darkwood]

Im on 3 physics forums, 2 quantum, and electrical is my side-line...... agree should be in electrical theory but if the question gets asked il do my best to answer although it wont improve his conduit bending its still feeding his desire to learn so nerrr!!!! :tounge_smile:

 

[Silly Sausage]

Im on 3 physics forums, 2 quantum, and electrical is my side-line...... agree should be in electrical theory but if the question gets asked il do my best to answer although it wont improve his conduit bending its still feeding his desire to learn so nerrr!!!! :tounge_smile:

Good for you mate. I love physics, quantum theory etc., but it is a bit pointless spouting such things to someone who can't grasp the basic concept of a simple circuit.
As for QT, what's the famous quote...'If you think you understand QT, you've no idea' something like that.
I'm sure you'll be able to enlighten me.

 

[Darkwood]

Although its quantum based the explan's were everyday, i call it my shock and awe approach if they still interested then and question correctly then im all too happy to oblige but if i sense its well beyond their thinking at least they will establish their level and i will advise where to find their feet, as regards to the O/P hes PM me and is interested in the deeper concept but whether he understands it or not is a different thing but thats where i started but in them days a calculator watch was the most help you had. (casio to the older members).

It might be a irritation i have but been taught at school and college bullcrap about electrons whizzing around really undermines the abilities of some ppl and treats them like muppets, remember Einstein himself failed maths because he never got the stimulus needed ... now what did happen to him????

 

[Silly Sausage]

Although its quantum based the explan's were everyday, i call it my shock and awe approach if they still interested then and question correctly then im all too happy to oblige but if i sense its well beyond their thinking at least they will establish their level and i will advise where to find their feet, as regards to the O/P hes PM me and is interested in the deeper concept but whether he understands it or not is a different thing but thats where i started but in them days a calculator watch was the most help you had. (casio to the older members).

It might be a irritation i have but been taught at school and college bullcrap about electrons whizzing around really undermines the abilities of some ppl and treats them like muppets, remember Einstein himself failed maths because he never got the stimulus needed ... now what did happen to him????

QueenZ, ignore this, nowt to do with you.

The 'real' world and the 'tiny' world are, at the moment, completely separate entities. Until we get unification!
Whilst I always encourage anyone's desire for knowledge, you need to have a certain level to be able to understand and absorb more deeper concepts, but there is no way one can even begin to explain QT via a forum or email or whatever.

Blue bit. That's just archaic modelling of the atomic world, but it works for starters. You can't drag E into the discussion, if you were stuck in a Patent office with his brain power, what would you think about?

 

[Darkwood]

QueenZ, ignore this, nowt to do with you.

The 'real' world and the 'tiny' world are, at the moment, completely separate entities. Until we get unification!
Whilst I always encourage anyone's desire for knowledge, you need to have a certain level to be able to understand and absorb more deeper concepts, but there is no way one can even begin to explain QT via a forum or email or whatever.

Blue bit. That's just archaic modelling of the atomic world, but it works for starters. You can't drag E into the discussion, if you were stuck in a Patent office with his brain power, what would you think about?

I see what your saying and would agree on most occasions but regarding this thread the OP was having trouble with the very concept of induction because of his teachings that electrons move (in a flowing sense) in a.c. circuits, without going too deep i explained that he has to give up the idea of electrons whizzing round as its this that is creating his confusion, and regarding my earlier posts and PM response from OP i believe ive given him the insight he needed even if he hasn't got the full grasp he has a better understanding which he can accept.
Had the O/P shown the inept mental abilities of a lesser primate then i would have avoided the deeper discussion, some questions cant be answered with mainstream physics and as ive seen many times only leaves the OP more confused and frustrated, and although deeper- the area of QT im relating to is mild and mixed with everyday examples can be visualised quite easy.

 

[RogertheBodger]

Got brain ache now - think I'm ready to be flung off the planet.

 

[Bluesknight]

The reason the wire does not burn up is because the induced voltage and current in the coil are in the opposite direction to the original voltage and current. This is referred to as back emf and limits the build up of current.

Electrons must flow or there is no current

 

[QueenZ]

I don't know HOW this thread got dumped here but darkwood has done a pretty good job explaining how it works...

Is it right to say that the electrons don't jiggle back and forth in an AC setup with an open circuit and they do in a closed one?

 

[Bluesknight]

With respect to current flow that is correct.