Grounding in electrical circuits

[sophiecentaur]

@Jim

That's a fair enough view but it doesn't really constitute Physics imho. You don't need Physics to fix your car electrics, usually, but there are a number of problems I have solved which have benefited a lot from something more than the 'complete circuit' idea.
This is supposed to be a Physics Forum - not a car fixit helpline. I think it only reasonable that people who present problems, based on Physics, should expect answers which are at least a bit demanding.

Is it showing off to tell people that they need to do more than first year Science and they will need some reasonable Maths if they are going to get a better understanding? Is it showing off to tell people that they will not be able to run a Marathon without some serious training? Or that they will need to learn to swim before they jump into the deep end of the pool?

Inverted snobbery never got anyone anywhere.

I agree that the New Math approach didn't work - but that isn't really a parallel. The 'why' is essential when you want to do more than arithmetic. There are very few valid arm waving 'explanations' to help someone perform a Fourier Transform or Correlation.

 

[sophiecentaur]

Gosh I must remember that little aphorism - it applies so well to other disciplines as well as maths.

"just sodding learn it. Then we can discuss it."
That gets my vote every time!

 

[jim hardy]

"""I think it only reasonable that people who present problems, based on Physics, should expect answers which are at least a bit demanding."""

Fair enough.



old jim

 

[Evil Bunny]

Does this mean that our current just changed?""

no, it just means the electrons are(or should we say charge is) are packed a little closer together inside the wire.
current will flow in accordance with Ohm's law just as it did before the strike.

Thank you Jim... This makes sense to me now. I can see now how we can have a complete circuit and still have a potential to ground. I never really thought of it that way until you made this statement.

I appreciate your way of explaining things... It is quite helpful to some of us.

On a side note... I think it is unwise to dismiss the importance of a complete circuit, especially when the discussion revolves around grounding. It is surprising to me how many people think that electricity wants to flow into the earth. This thread hits on the heart of the matter where "circuit electricity" blends with "static electricity". While some may think this is a trivial thing, it is widely misunderstood in my experience.

Thank you to all who have contributed to this. I hope this thread has helped people to have a better understanding of the concept. It has definitely helped me...

As Studiot would say... Go well

 

[sophiecentaur]

"a complete circuit" is not 'dismissable'. It's just the first step in getting to grips with electronics - and no more.

 

[jim hardy]

Thank you Jim... This makes sense to me now. I can see now how we can have a complete circuit and still have a potential to ground. I never really thought of it that way until you made this statement.

I appreciate your way of explaining things... It is quite helpful to some of us.

....

Thank you to all who have contributed to this. I hope this thread has helped people to have a better understanding of the concept. It has definitely helped me...

As Studiot would say... Go well

Thank you EB for your kind, kind words.
I believe we need simple models to get our thinking in order.part of a good education is an awareness of just how meager our knowledge really is.

i think so long as we keep in mind that every step in our learning process invites another , we'll be okay. It's dangerous to think we have arrived at some summit of knowledge. At least for me, it always results in some humbling event.
I once read in an erudite journal a statement to this effect:
"Electrical energy does not flow along wires, it flows in the electric and magnetic field surrounding them."
Now THERE was a corker, for the electrons-in-motion (oops charge-barely-in-motion) model that i grew up with doesn't look outside the wire at all.

But it helps people resolve apparent logical conflicts like you described.

So - keep on refining your mental models of how things work.
Maybe you'll explain to me about that energy being in the field along the wire...

old jim