Direction of current flow

[GoldDigger]

Funny you should mention that. I was once taking an oral exam in E&M and had to apply the right hand rule to answer the question.
Since I had the chalk in my right hand I used my left instead.

 

[jumper]

I have often wondered why the teachers haven't changed on or the other so both match. It would be a simple matter of calling the right hand rule the left hand rule etc.

Too many text books and information has been written using conventional flow to switch to only using electron flow and vice versa.

As Gar stated people should know both and just use whatever one is being used by an author or teacher.

I personally prefer electron flow, but I have no real problem with either.

 

[Frank DuVal]

To clarify spark plug wiring, the center electrode needs to be negative with respect to the shell (engine block/chassis) so the electrons emit from the sharp center electrode and target the flat larger shell electrode.

The standard style ignition coil is not connected from the primary to the shell of the coil. That is why there are - and + terminals on it (or in the case of Ford, Bat and Dist.). It can be wired for positive or negative ground. If you change the polarity of the system, just swap the wires on the + and - terminals. People do this all the time when putting in 12 volt batteries/negative ground alternators in 6 volt vehicles (instead of just fixing the wiring so the 6 volt system works like it did when new - rant ).

If the coil polarity is backwards (putting the high voltage positive on the center electrode of the plug), the output voltage remains the same, but due to issues getting the plug to fire you will see reduced power and high speed problems. In old texts you will see the carbon pencil test, which side the feather of the spark shows polarity. I just look at the primary terminals, less playing with holding high voltage leads!:thumbsup:

Yes, most older vehicle chassis carry current. The modern exception is most vehicle computer wiring is through a wired ground path to keep down noise and voltage drop issues.

 

[kwired]

Ironically 4 pages and I didn't see where anyone focused on the word theory. Someone correct me if I am wrong, but the last I really paid attention, it was becoming accepted that electrons and protons may not be particles. They may be waves. So everything could be energy, not substance. Then again, every atom could be a universe. I am not pointing this out to be argumentative or weird, but to point out that as far as I know, we can try to put electrical flow in to concepts we can understand, and it can fit on all the levels we need it to for our current uses of energy. That doesn't make any of us right. I think the most important thing in this thread is that electricity is looked and and taught with conventional flow and with electron flow. Regretfully to me, we are taught the very first steps, magnetism, lines of flux, etc. utilizing conventional flow, and then without a lot of focus, everything else we learn is electron flow. I have often wondered why the teachers haven't changed on or the other so both match. It would be a simple matter of calling the right hand rule the left hand rule etc.

My reply to the bold text is where does mass come from if the subatomic parts are energy only?

 

[mgookin]

My reply to the bold text is where does mass come from if the subatomic parts are energy only?

Waves are not matter. Waves are a means in which matter travels. Electrons and protons have mass!

 

[kwired]

Waves are not matter. Waves are a means in which matter travels. Electrons and protons have mass!

So if they have mass does that make them particles (substance) of some sort or are they energy?

I think you are saying the sub atomic components are particles and the waves they are carried on are energy?

 

[mgookin]

So if they have mass does that make them particles (substance) of some sort or are they energy?

I think you are saying the sub atomic components are particles and the waves they are carried on are energy?

Yes they are particles (substance). Particles in motion have energy (e=mc^2). The wave itself is not energy just as a car in a straight line does not make the line energy but the car in motion has energy (like when it hits a tree).

 

[Strathead]

Yes they are particles (substance). Particles in motion have energy (e=mc^2). The wave itself is not energy just as a car in a straight line does not make the line energy but the car in motion has energy (like when it hits a tree).

That is the predominate THEORY today. And it will be until it isn't. To speak with such surety is something. The world was flat before it was round. The Big Bang is a fact and then a theory. As I said, for our purposes Electrons as a particle works to explain the observations that we make, but it doesn't make it a fact.

 

[ggunn]

That is the predominate THEORY today. And it will be until it isn't. To speak with such surety is something. The world was flat before it was round. The Big Bang is a fact and then a theory. As I said, for our purposes Electrons as a particle works to explain the observations that we make, but it doesn't make it a fact.

Waves and particles are models, and models are all we have. As long as the model explains the observances accurately, it makes no difference whatsoever whether the models are "correct" or not.

 

[GoldDigger]

Waves and particles are models, and models are all we have. As long as the model explains the observances accurately, it makes no difference whatsoever whether the models are "correct" or not.

+1

The ancient Greeks had a model for why objects all fell and some objects floated in water while others did not.
Their model said that everything had a property called gravity or "heaviness" which made it fall. Lead bricks had more gravity than feathers.
And in addition things that floated had a separate property called levity or "lightness" which made them float but was totally unrelated to gravity.

The did not manage much in the way of verifiable predictions with this model, but it made for good discussions.
Then Archimedes came along and discovered specific gravity, giving them the analytic tools they needed to replace the two separate properties with a single one.
The model became much simpler.
So in addition to an accurate description of observations, simplicity and even elegance form criteria for evaluating two theories against each other.

 

[FionaZuppa]

Waves and particles are models, and models are all we have. As long as the model explains the observances accurately, it makes no difference whatsoever whether the models are "correct" or not.

??
i think you mean to say, "makes no diff what model you choose to use if both explain the observations". it certainly does matter if the model is not correct.

 

[Strathead]

Waves and particles are models, and models are all we have. As long as the model explains the observances accurately, it makes no difference whatsoever whether the models are "correct" or not.

Thank you, that is basically what I was trying to say.