NEETS Manual Defintions

WBahn

Joined Mar 31, 2012
30,045
My other comment was a little long winded, if you don't want to read any of that I understand haha. The big thing I was trying to say was a lot of books just seem flat out wrong making statements like "a negative current means the real or actual current is going the other way" so I would prefer to get any book recommendations that go into the details and do so correctly, if you have any recommendations. Like I said Nilsson seemed pretty good.
If Nilsson seemed pretty good, then go with it.
 

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sarah_c

Joined Jul 13, 2020
24
If Nilsson seemed pretty good, then go with it.
Okay, I mean does that book seem better to you?

I read one that said: Current is defined moving opposite to electrons. If you get a negative current, that means the actual current goes the opposite way.

Then Nilsson says something like: You assign a reference arrow. The value of the current will be positive if either positive charge moves in the direction of that arrow or negative charge moves opposite. The value of the current will be negative if either negative charge moves in the direction of that arrow or negative charge moves opposite.

The Nilsson explanation seems better because to my understanding, positive current is not anymore "actual current" than negative current is "actual current" so the first definition is vague. What do you think? Any other recommendations?
 

WBahn

Joined Mar 31, 2012
30,045
Nilsson's a decent book. They are sloppy with their units, but virtually every electrical engineering text is. You might visit the library at a university that has an electrical engineering department and see if they have a collection of introductory circuit analysis textbooks and then start reading through the introductory material to find ones that you thing are adequate for your purposes.
 

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sarah_c

Joined Jul 13, 2020
24
Nilsson's a decent book. They are sloppy with their units, but virtually every electrical engineering text is. You might visit the library at a university that has an electrical engineering department and see if they have a collection of introductory circuit analysis textbooks and then start reading through the introductory material to find ones that you thing are adequate for your purposes.
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This one is from two authors named Sadiku and Alexander. As you see they correctly assert the negative sign of an electrons charge, but then proceed to say "It is conventional to take the current flow as the movement of positive charge." I don't know how I feel about that statement. It seems the more accurate and complete statement would be "It is conventional to point the arrow of positive current flow in the direction that positive charges would move." Again, they have a similar diagram as this website which shows just an arbitrary i pointing opposite electrons, when i doesn't have to point opposite electrons. You can point an arbitrary arrow labeled i in the direction of electrons too. Especially when they later show that you can represent a current as positive one way or negative the other way. Both of these currents don't move opposite electrons. Similarly, both don't point in the direction of positive charge. Would you agree the Nilsson seems better than this definition as well? I will look for more, but this seemed to be recommended on Reddit posts I could see as well.
 

WBahn

Joined Mar 31, 2012
30,045
What is your point? That you don't like the way this author or that author phrases something? Fine. Pick one that you are happy with and move on. Or write the author and explain to THEM how you think they should phrase it in their next edition -- there's even a small chance that some of them might actually do so. But going on and on and complaining about it on an internet forum is not going change anything. Either you understand enough to grasp what they are trying to say, regardless of how imperfectly you feel that they have said it, or you don't. If you do, then give it a rest and move on. If you don't, then at this point there is virtually no chance that continuing is going to change that.
 

Thread Starter

sarah_c

Joined Jul 13, 2020
24
What is your point? That you don't like the way this author or that author phrases something? Fine. Pick one that you are happy with and move on. Or write the author and explain to THEM how you think they should phrase it in their next edition -- there's even a small chance that some of them might actually do so. But going on and on and complaining about it on an internet forum is not going change anything. Either you understand enough to grasp what they are trying to say, regardless of how imperfectly you feel that they have said it, or you don't. If you do, then give it a rest and move on. If you don't, then at this point there is virtually no chance that continuing is going to change that.
That is a good idea to reach out to the author. I was just wanting your opinion on which books you think are the best. I think I understand enough to grasp what they are saying. I mean earlier in our discussion I wrote about how I understood things and you said it was fine. Ultimately, my understanding is that positive current points in the direction of positive charge, and negative current points in the direction of negative charge. The sign of the current represents a net flow of that sign of charge in the direction of that arrow( a negative current represents a net flow of negative charge in the direction of the arrow). This seems to be correct from this conversation, but I was just wondering which book you like best.

I personally feel I understand what these books are saying, but I was hoping you could confirm based on my explanation of that book if I am getting the right idea. I know you confirmed my previous explanations were correct earlier on, just thought it might be good to look at how one might respond to certain literature.
 

Thread Starter

sarah_c

Joined Jul 13, 2020
24
What is your point? That you don't like the way this author or that author phrases something? Fine. Pick one that you are happy with and move on. Or write the author and explain to THEM how you think they should phrase it in their next edition -- there's even a small chance that some of them might actually do so. But going on and on and complaining about it on an internet forum is not going change anything. Either you understand enough to grasp what they are trying to say, regardless of how imperfectly you feel that they have said it, or you don't. If you do, then give it a rest and move on. If you don't, then at this point there is virtually no chance that continuing is going to change that.
So disregarding the books, because well, who cares. The bottom line seems to be this. If you use current like the way NEETS does it, than you are being inconsistent at the end of the day. If you want to point your current arrow in the direction of electrons using the convention that everyone else uses, than you must do so with a negative value, and that is okay. However, the more traditional way to interpret a negative value is to say the net flow of positive charge moves the other way. So it is not wrong to say a negative value represents a net flow of negative charge, however it does not directly follow in applications outside of electric current, and this is where I am thinking your comment about "not logically following" came from. It doesn't mean the interpretation is wrong, it just sounds "weird" since for example water current doesn't have a negative form of water.

Thus if you have a negative actual current to the right, electrons go right, net positive charge goes left, net negative charge goes right.

A positive actual current to the right means electrons go left, net positive charge goes right, net negative charge goes left.

You may come across authors and people who are sloppy with including the word positive and negative with their explanations, but you should be able to understand they are usually only interested in positive current, and thus the sign gets dropped in conversation.

If this summary is correct, than this topic makes perfect sense, thanks to your help!
 
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