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

[QueenZ]

Hello, I am struggling to understand how electricity is generated in an AC generator... I know that there is a coil of wire and a magnet, and both of them have their own magnetic fields and as the magnet moves into the coil's magnetic field, it causes electrons to move in that coil. Well if that is right, then why is there no current flowing if the circuit is open? It only seems to be the case if the circuit is closed. I think it's called Electromotive force but how does it work? Does it literally PUSH the electrons? what difference does it make if we have a closed or an open circuit? If it PUSHES the electrons even in an open circuit then the wire would get hot and it would burn, no?

To illustrate this, I've put together 2 pictures, in which we have a closed circuit (we have current flowing) and in the other one we have the same thing but with an open circuit (I guess there's no current flowing there? why?).

Are the electrons moving or not in the second picture? why?

 

[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.