Voltage and Current Understanding

[crutschow]

...............................

The Wikipedia entry for electron drift velocity shows an example calculation of a 3amp current flowing through a 1mm wire results in the electrons taking 1hour to traverse a distance of 1 meter. A surprisingly large bulk of electronic hobbyists don't realize this.

Makes you realize the huge number of free electrons contained in a conductor. One ampere is one coulomb per second or 6.241 × E18 electrons per second. So since three amperes for one hour moves 6.74 x E22 electrons 1 meter, then 1 meter of a 1mm wire contains that number of free electrons.

 

[nicksydney]

Thanks all for taking time in replying to my question. After reading all the answers I decided to create a simple circuit using breadboard to enable me to understand more better about Voltage and Current. I created a breadboard a power source of 6v with 2 LED (in series) and a potentiometer and following are few things that I observe:

*****************
Voltage measurement
*****************

The way I measure the Voltage is to connect each probe to the LED leg. For LED 1 & LED 2 I'm getting the same reading (for Voltage) which is exactly what the theory says that 'serial resistors will read the same Voltage'. I'm also getting the same reading for Current which is correct ?.

The way I'm using multimeter to measure the Voltage coming out from the potentiometer is placing one probe in 'incoming (+)' leg and the other to the 'output' leg (I've included the picture of the potentiometer in the attached picture and I've labelled the legs) and I'm getting a lower voltage compared to the source voltage (which is as expected), two things that I notice that was interesting
1. If I place one probe on the 'incoming (+)' and the other to the 'ground' I'm getting the Voltage reading exactly the same as the Voltage reading of the battery
2. When I reduce the resistance from the potentiometer (when I reduce the potentiometer I can see the LED light up brightly) the Voltage reading also dropped and when I increase the resistance the Voltage also increases, is this right ?
3. crutschow mention:

The sum of the drops equals the source voltage.

so this means the sum of Voltage of LED1 and LED2 = The Voltage output recorded from the 'output' of the potentiometer ?

I've attached some pictures of the breadboard setup and also some labelling that I've done.

Appreciate your feedback and suggestion

Thanks

View attachment 62231


View attachment 62232

View attachment 62233

 

[DerStrom8]

DerStrom8,
That is all correct as far as the external current goes. But, the +ions that give up their electron for external current have to go to the cathode where they receive a returning electron and get neutralized. That path is within the battery, and is an example of a positive charge moving. This has to happen, otherwise the anode would clog up with +ions and the cathode would clog up with electrons. Therefore an internal current of positive charges exists within the battery to neutralize the internal charge build up. This positive charge internal current has to equal the external negative charge current.

Ratch

The +ions, after giving up an electron, do not move much within the battery. They start in the oxidizer (which is on the cathode) and remain on the cathode once the electron is taken. The current flow we really care about is on the outside, not the inside. Conventional current flow is said to go from the cathode, through the circuit, and back into the anode, which is just plain wrong. The current (defined as the flow of electrons) exits the anode, flows through the circuit, and moves back to the cathode. There is no way to argue that--it is a fact.

 

[DerStrom8]

The way I measure the Voltage is to connect each probe to the LED leg. For LED 1 & LED 2 I'm getting the same reading (for Voltage) which is exactly what the theory says that 'serial resistors will read the same Voltage'. I'm also getting the same reading for Current which is correct ?.

In a series circuit, each resistor should produce a voltage drop, and for that reason will not measure the same. However, you are not measuring between the resistors, you're measuring the LEDs. LEDs have very little internal resistance, and thus will not have a voltage drop. If you replace them with resistors, i would expect you to get different voltages. That is if you're measuring between the test point and ground. If you're measuring across the resistors (+ probe on one side and - on the other), and the resistors have the same resistance, yes--the voltage drop will read the same for both of them. However, saying 'serial resistors will read the same Voltage' will need a specification. If they are the same resistance, and you're only measuring voltage ACROSS them, then yes, it's right. However, if you're measuring between the resistor leg and ground, it will NOT be the same.

And yes, current through a series circuit will always remain the same.

 

[Ratchit]

DerStrom8,

The +ions, after giving up an electron, do not move much within the battery.

I beg to differ. See https://www.explainthatstuff.com/batteries.html under the paragraph "Chemical Reactions". We are talking about a chemical battery, not a dynamo. In electrolysis, ions move.

The current flow we really care about is on the outside, not the inside.

Care or not, the internal current has to match the external current.

Conventional current flow is said to go from the cathode, through the circuit, and back into the anode, which is just plain wrong.

Not quite accurate. The conventional current/voltage (CCV) method mathematically assumes positive to negative charge movement of a voltage source. The CCV does not concern itself with the actual polarity or the physical direction of the charge carriers. It only give a calculated value from which the user can then deduce what the true direction of charge flow is.

The current (defined as the flow of electrons) exits the anode, flows through the circuit, and moves back to the cathode. There is no way to argue that--it is a fact.

Yes, that is what happens externally. No one denies that fact. But there is an internal current also, whether of interest or not.

Ratch

 

[DerStrom8]

DerStrom8,
I beg to differ. See https://www.explainthatstuff.com/batteries.html under the paragraph "Chemical Reactions". We are talking about a chemical battery, not a dynamo. In electrolysis, ions move.

I don't think that's entirely correct. When the oxidizer atoms (parts of the + electrode material) give off electrons, they become ions, but they do not "move" towards the cathode. They are part of the cathode. Current is defined as the "Movement of electrons", which is what is really important.

Care or not, the internal current has to match the external current.

Sure, but it is not important. One could be an electronic engineer his/her entire life and he/she would not need to know about the positive ions within a battery. The only thing that is really important to know in a circuit is what happens on the outside of the battery. It is necessary to know that the current flows from negative to positive, and that the voltage potential from the cathode to the anode is a positive value.

Not quite accurate. The conventional current/voltage (CCV) method mathematically assumes positive to negative charge movement of a voltage source. The CCV does not concern itself with the actual polarity or the physical direction of the charge carriers. It only give a calculated value from which the user can then deduce what the true direction of charge flow is.

I am not arguing with you saying that conventional current flow can't be used in math. I'm saying it can't be assumed to be true in the physical world. Current does not flow from + to -. That's all I'm trying to say.

Yes, that is what happens externally. No one denies that fact. But there is an internal current also, whether of interest or not.

Ratch

I agree, there is an internal current, but it is very small. It is negligible and does not really affect the operation of a battery when considering what's on the outside.

 

[Ratchit]

DerStrom8,

I don't think that's entirely correct. When the oxidizer atoms (parts of the + electrode material) give off electrons, they become ions, but they do not "move" towards the cathode. They are part of the cathode. Current is defined as the "Movement of electrons", which is what is really important.

Obviously the anode material cannot be part of the ions traveling to the cathode. There won't be any material left on the anode before long if that happened. The link does not say that happens. No doubt, a secondary reaction in which the electrolyte gives up an electron to the anode, and then moves to the cathode to receive a replacement electron occurs. The point is that there if a current of positive ions within the battery.

Current is defined as the movement of charge carriers per unit of time. That includes the positive charge carriers, too.

One could be an electronic engineer his/her entire life and he/she would not need to know about the positive ions within a battery. The only thing that is really important to know in a circuit is what happens on the outside of the battery.

Unless you are a battery engineer. That is becoming an important field of endeavor these days.

I am not arguing with you saying that conventional current flow can't be used in math. I'm saying it can't be assumed to be true in the physical world. Current does not flow from + to -. That's all I'm trying to say.

Not that CCV cares, but current does exist in the + to - if the charge carriers are positive. Not all electric circuits are through metallic wires, which are predominently negative charge carriers.

I agree, there is an internal current, but it is very small. It is negligible and does not really affect the operation of a battery when considering what's on the outside.

The internal battery current has to equal the external battery current OR Kirchoff's current law will be violated.

Ratch

 

[DerStrom8]

DerStrom8,
Obviously the anode material cannot be part of the ions traveling to the cathode. There won't be any material left on the anode before long if that happened. The link does not say that happens. No doubt, a secondary reaction in which the electrolyte gives up an electron to the anode, and then moves to the cathode to receive a replacement electron occurs. The point is that there if a current of positive ions within the battery.

Why do you think batteries die? It is because as the oxidizer gives off electrons, it decays. The remaining ions attract the electrons to the cathode, but the material still gives way a little bit. After a period of time, it will lose too much of its oxidizer to sustain current flow.

Current is defined as the movement of charge carriers per unit of time. That includes the positive charge carriers, too.

Ok, I'll give you that, but it does not change my main point.

Unless you are a battery engineer. That is becoming an important field of endeavor these days.

Now you're just picking nits.

Not that CCV cares, but current does exist in the + to - if the charge carriers are positive. Not all electric circuits are through metallic wires, which are predominently negative charge carriers.

Sure, but in a simple series circuit with, say, a battery and a resistor (as I discussed earlier), the dominant, important charge carriers are electrons. I'm pretty sure I went over this before....

The internal battery current has to equal the external battery current OR Kirchoff's current law will be violated.

Ratch

Yes, but the important internal battery current is the electrons flowing from the oxidizer to the anode. Not the "movement" of +ions.

 

[Jon Wilder]

Quite honestly I'm not sure why anyone even cares about the chemical reaction and the activity which happens in a battery. Unless you are a battery engineer it's not something you really need to know. Just know that externally, electrons flow from the negative terminal, through the external path which exists between the battery's terminals, and returns back to the positive terminal until the charge difference that exists between the terminals is depleted.

 

[Ratchit]

DerStrom8,

Why do you think batteries die? It is because as the oxidizer gives off electrons, it decays. The remaining ions attract the electrons to the cathode, but the material still gives way a little bit. After a period of time, it will lose too much of its oxidizer to sustain current flow.

I did not know we were talking about dying batteries.

Ok, I'll give you that, but it does not change my main point.

Which was?

Now you're just picking nits.

Well, you cannot aver that one particular aspect of EE like circuit analysis is more important or should deserve more attention than another less interesting branch of electronics.

Sure, but in a simple series circuit with, say, a battery and a resistor (as I discussed earlier), the dominant, important charge carriers are electrons. I'm pretty sure I went over this before....

As did I. In a equally simply circuit, a battery in series with another resistor, a slab of PNP semiconductor material will have positive holes as the predominant charge carriers.

Yes, but the important internal battery current is the electrons flowing from the oxidizer to the anode. Not the "movement" of +ions.

As I stated before, a battery is a chemical entity, not a dynamo. Ions have to be created and move in order for it to work. Also they have to balance with the external flow of electrons they cause. If electrons flowed within the battery, then no ions would need to exist. But since there are no magnetic fields with a battery like there is in a dynamo to move the electrons along, that cannot happen.

Ratch

 

[DerStrom8]

DerStrom8,
I did not know we were talking about dying batteries.

Come on Ratch. I'm sure you know as well as I do that ALL batteries in the real world die after a certain amount of use!

Which was?

That the carriers and current flow we really care about is the flow of ELECTRONS in a simple series circuit. How many times do I need to repeat that?

Well, you cannot aver that one particular aspect of EE like circuit analysis is more important or should deserve more attention than another less interesting branch of electronics.

My point has nothing to do with types of electrical engineering. My point was that the "movement" of +ions is negligible and is, in fact, unimportant in most cases.

As did I. In a equally simply circuit, a battery in series with another resistor, a slab of PNP semiconductor material will have positive holes as the predominant charge carriers.

I'm not talking about "slabs of PNP semiconductors"! I'm talking about a basic series circuit with only a battery and a resistor. I'm not talking about semiconductors here!

As I stated before, a battery is a chemical entity, not a dynamo. Ions have to be created and move in order for it to work. Also they have to balance with the external flow of electrons they cause. If electrons flowed within the battery, then no ions would need to exist. But since there are no magnetic fields with a battery like there is in a dynamo to move the electrons along, that cannot happen.

Ratch

Ions are not just "created". The electrons are stripped, and pushed/pulled around the circuit, which is current flow. When the electrons are taken from the oxidizer, it leaves positively charged ions at the cathode, which attract (pull in) electrons. However, in order for the electrons to get back to the cathode, they must go through the circuit first. That's how batteries work. Period. The only "flow" of +ions is a tiny amount of movement within the battery, when the electrons coming to the cathode get close enough to pull them (as they are pulling the electrons). The positive ions DO NOT move around the circuit--only slightly within the battery.

 

[Ratchit]

DerStrom8,

Come on Ratch. I'm sure you know as well as I do that ALL batteries in the real world die after a certain amount of use!

Certainly that is true. I just did not know that we were discussing dead and dying batteries.

That the carriers and current flow we really care about is the flow of ELECTRONS in a simple series circuit. How many times do I need to repeat that?

Well, "we" does not include me. I am interested in all aspects charge carrier movement.

My point has nothing to do with types of electrical engineering. My point was that the "movement" of +ions is negligible and is, in fact, unimportant in most cases.

And my point is that the ion current has to equal the external electron movement, and cannot be ignored if proper understanding is needed.

.
I'm not talking about "slabs of PNP semiconductors"! I'm talking about a basic series circuit with only a battery and a resistor. I'm not talking about semiconductors here!

And does not a slab of PNP semiconductor have resistance?

Ions are not just "created". The electrons are stripped, and pushed/pulled around the circuit, which is current flow.

I assume you are referring to the external flow. Except for the "current flow" phrase, I can agree with that.

When the electrons are taken from the oxidizer, it leaves positively charged ions at the cathode, which attract (pull in) electrons. However, in order for the electrons to get back to the cathode, they must go through the circuit first. That's how batteries work. Period.

When electrons are taken from the electrolyte in the vicinity of the anode, which supplies electrons to the external circuit, ions are created and travel internally through the battery to the cathode where they pick up a returning electron and become neutralized.

The only "flow" of +ions is a tiny amount of movement within the battery, when the electrons coming to the cathode get close enough to pull them (as they are pulling the electrons).

For every electron that travels the external circuit, a positive ion has to make the trip from the anode to the cathode within the battery. Otherwise the charges would accumulate, which does not happen.

The positive ions DO NOT move around the circuit--only slightly within the battery.

Only electrons move external to the battery. But the +ion current has to match the external electron current. The electrons cannot move within the internal battery because there is nothing to propel them like there is in a dynamo. They have to go through the chemical ion neutralization process to get back to the anode.

Ratch

 

[DerStrom8]

DerStrom8,
Certainly that is true. I just did not know that we were discussing dead and dying batteries.

I was talking about any battery. Even a brand new battery starts dying as soon as it is made.

Well, "we" does not include me. I am interested in all aspects charge carrier movement.

I meant "we" as engineers in general. Most engineers do not need to know about how a battery works--only those who study them as part of their job. In most cases, though, one does not need to know about it.

And my point is that the ion current has to equal the external electron movement, and cannot be ignored if proper understanding is needed.

Yes, I agree that the same number of ions will be at the cathode as the number of electrons stripped from the oxidizer. However, it is not the ion "flow" that does the work--it is the electron flow through the circuit. That's what I was focusing on and explaining.

And does not a slab of PNP semiconductor have resistance?

Of course it has resistance, just like anything else in the universe. But as I have said countless times already, I'm talking about a basic resistor, NOT a "slab of PNP semiconductor"!

I assume you are referring to the external flow. Except for the "current flow" phrase, I can agree with that.

Of course I'm talking about external flow. What have I been talking about for the past 25 posts???

When electrons are taken from the electrolyte in the vicinity of the anode, which supplies electrons to the external circuit, ions are created and travel internally through the battery to the cathode where they pick up a returning electron and become neutralized.

Woah, electrons are NOT taken from the electrolyte. The electrolyte is what strips the electrons from the oxidizer. Once stripped, the electrons flow through the electrolyte to the anode, and out the terminal. Then they flow around the circuit, back into the cathode, and "meet back up" with the ions. Other than the part about electrons being taken from the electrolyte, I agree with that quote.

For every electron that travels the external circuit, a positive ion has to make the trip from the anode to the cathode within the battery. Otherwise the charges would accumulate, which does not happen.

yes, I agree. But as I said before, it is not the movement of ions that does the work--it's the movement of the electrons. That is why, for this thread, I have been discussing electrons--THEY are what are important in this case, NOT the ions.

Only electrons move external to the battery. But the +ion current has to match the external electron current. The electrons cannot move within the internal battery because there is nothing to propel them like there is in a dynamo. They have to go through the chemical ion neutralization process to get back to the anode.

Ratch

Of course. I completely agree with that. And it is the movement of electrons OUTSIDE of the circuit that is important.

 

[Sceadwian]

For your example (which was a good one BTW) we have few hobbyists who know how fast charges travel down a wire. But we have zero hobbyists who need to use this information for any practical project they are building

Ahh but MrAl, I think you're dead wrong about that. You're thinking about electronics strictly from a 'get it done' perspective, I and many hobbyists are also here for learning without boundaries, if it applies regardless of how esoterically so to electronics I follow up on it. If you want to produce electronic gadgets yes there is a set method for doing this as efficiently as possible which requires very little true understanding. Understanding electronics is my hobby more than anything else, and it is a great benefit to ANY individual to learn as much about their chosen field of study even outside of it's direct implications for their uses as it will change their perspective on what is and is not possible and produces a much better overall educated individual in the end.

This forum could mint electrical engineers by the gross if they wanted to, and they'd mint more widget makers without thought of why, and how most efficiently to do things and what alternate methods there are available, for a large number of the posts on this forum quiet often the answer is to not approach it from the perspective they came in with, and it's always people that know the least about the most variety of topics.

I do however think we can lock Destrom and Ratchit in a room right now with plenty of water, throw away the key, give it a few weeks, and the one that survives will have figured out how to pick the lock using the bones of the other after they've cannibalized them to survive =)

I hope to partake in fewer and fewer of those types of conversations in the future as I've over the course of my visits here I have learned that a long argument is a lost argument.

All true good debate and meaning in science is simple and straight forward, if you're spending this many posts nit picking every individual line from another's post it's probably time to stop and take a real solid look at the image you're projecting and regroup your thoughts in a more basic and cohesive way. I'm not even sure if I can follow their last few posts, there certainly is no meaning or conclusions to derive from anything having been said so far, which means it's not constructive.

Quite honestly I'm not sure why anyone even cares about the chemical reaction and the activity which happens in a battery. Unless you are a battery engineer it's not something you really need to know. Just know that externally, electrons flow from the negative terminal, through the external path which exists between the battery's terminals, and returns back to the positive terminal until the charge difference that exists between the terminals is depleted.

Jon... If you look at a battery from that standpoint you'd be like every engineer that ever made a cordless phone that uses a NiMH battery that is trickle charged constantly on it's base which causes them to fail after 1 year of use because the chemistry is destroyed from the subtle overcharge, a properly designed NiMH charger would let the battery last 5+ years.

It is paramount to someone using electronics that uses a battery to know how they work. Nowdays you can get some pretty sophisticated charge controllers which take the need for this knowledge away, but if you don't know in the first place why you need to use a charge controller because you don't know anything about batteries then you will be a horrible engineer!

You know why those charge controllers are being used? Because soem electrical engineer that don't know anything about battery chemistry improperly used Lithium Ion batteries which were caused to explode or burst into flames because they didn't know anything about battery chemistry proper utilization and charge control methods!

Too much in teaching I see 'black boxing' of ideas and concepts like this, and it results in crappy products to end users because the education system has failed to see that there is no way to dumb down this stuff, you gotta know a lot to do ANYTHING well.

 

[nicksydney]

Hi all,

The discussion is interesting but it's beyond me at this stage I know that battery is power source the discussion is really confusing me. It would be easier for me to follow the thread if we can discuss about the circuit that I've setup in the breadboard with the picture that I've posted so I can follow the discussion again

Thank you for your help.

Cheers

 

[Jon Wilder]

Jon... If you look at a battery from that standpoint you'd be like every engineer that ever made a cordless phone that uses a NiMH battery that is trickle charged constantly on it's base which causes them to fail after 1 year of use because the chemistry is destroyed from the subtle overcharge, a properly designed NiMH charger would let the battery last 5+ years.

It is paramount to someone using electronics that uses a battery to know how they work. Nowdays you can get some pretty sophisticated charge controllers which take the need for this knowledge away, but if you don't know in the first place why you need to use a charge controller because you don't know anything about batteries then you will be a horrible engineer!

You know why those charge controllers are being used? Because soem electrical engineer that don't know anything about battery chemistry improperly used Lithium Ion batteries which were caused to explode or burst into flames because they didn't know anything about battery chemistry proper utilization and charge control methods!

Too much in teaching I see 'black boxing' of ideas and concepts like this, and it results in crappy products to end users because the education system has failed to see that there is no way to dumb down this stuff, you gotta know a lot to do ANYTHING well.

And it's a good thing I don't manufacture anything which requires a rechargeable battery.

Scead...while I do agree that there is a minimum prerequisite knowledge base that one must have in order to understand what they're doing in electronics (such as learning general programming concepts as they apply to all microcontrollers in order to know how to figure out how to apply your uC's instruction set in a way that bridges the gap between the machine level and the human perceivable level), there is absolutely zero reason for one to know every single little particle down to level zero about electronics off the top of their head in order to engineer a well designed circuit. While I understand you are a big proponent of "zero boundaries" learning, that doesn't mean that it's fair to others for you to cram it down others' throats and make them feel as if they have to have the same attitude you have about it in order to succeed in the field of electronics. Furthermore, trying to start beginners who don't even yet know what an electron or an ion even is out with advanced engineering stuff is never a good idea. The human brain is simply not capable of learning this way. This is why the school system is set up the way it is...you start off with elementary basics first, then move onto the next higher knowledge level once a thorough understanding of the elementary basics is obtained. In order for a person to understand something on a higher level, one must understand things on the lower level first in order for any of it to make any sense.

Put simply...you have to learn to crawl before you learn to run.

 

[Ratchit]

DerStrom8,

...However, it is not the ion "flow" that does the work--it is the electron flow through the circuit.

Yes, but if the ion flow stops, so does the external electron flow.

...I'm talking about a basic resistor, NOT a "slab of PNP semiconductor"!

It is still a resistance. Not a commercial resistor, but still a resistance.

Woah, electrons are NOT taken from the electrolyte. The electrolyte is what strips the electrons from the oxidizer. Once stripped, the electrons flow through the electrolyte to the anode, and out the terminal. Then they flow around the circuit, back into the cathode, and "meet back up" with the ions. Other than the part about electrons being taken from the electrolyte, I agree with that quote.

I am calling the oxidizer, stabilizers, fillers, and anything else between the cathode and anode an electrolyte. I guess we are going to have to disagree about whether the electrolyte gives electrons to the anode and takes them back from the cathode. And whether electrons travel internally through the electrolyte instead of ion generation and ion neutralization occurring.

That is why, for this thread, I have been discussing electrons--THEY are what are important in this case, NOT the ions.

And it is the movement of electrons OUTSIDE of the circuit that is important.

And if the electrons cannot move outside of the battery without ions moving inside the battery, then the ions are just as important.

Ratch

 

[DerStrom8]

Hi all,

The discussion is interesting but it's beyond me at this stage I know that battery is power source the discussion is really confusing me. It would be easier for me to follow the thread if we can discuss about the circuit that I've setup in the breadboard with the picture that I've posted so I can follow the discussion again

Thank you for your help.

Cheers

Sorry to get so far off topic, Nick. I guess this really turned into more of an argument between members then helpful replies. I'm going to respond to Ratch's latest post, and then I'll stop my end of the argument.

DerStrom8,
Yes, but if the ion flow stops, so does the external electron flow.

Well yes, but that is not the point. I think you've completely lost track of what we're actually talking about here.

It is still a resistance. Not a commercial resistor, but still a resistance.

Sure, but a slab of a PNP semiconductor (which, by the way, is not just a "slab"--it's made up of three parts, but I'm hoping you already know that) has a lot more variables and factors that come into play, whereas a basic resistor does not. I'm using SIMPLE examples to try to help the OP, and IMHO, you're only making things more confusing for him.

I am calling the oxidizer, stabilizers, fillers, and anything else between the cathode and anode an electrolyte.

Now that's just plain wrong. The electrolyte is a specific element that strips the electrons from the oxidizer. You can't just pretend everything between the cathode and anode is an electrolyte--that's 100% incorrect. There are four main parts in a battery--The positive electrode, the oxidizer, the electrolyte, and the negative electrode. You can't just say that everything between the electrodes is the electrolyte--that's only a part of it.

I guess we are going to have to disagree about whether the electrolyte gives electrons to the anode and takes them back from the cathode. And whether electrons travel internally through the electrolyte instead of ion generation and ion neutralization occurring.

No need to disagree. They are both correct. When an atom loses an electron, it becomes positively charged, due to the fact that it now has more protons than electrons. This makes it a positive ion. The electrons, which were stripped from the oxidizer, flow through the electrolyte and are repelled from the negative electrode (like charges repel), flow through the circuit, and are pulled back into the cathode, where the positive ions are (opposite charges attract). Since the ions are positive, they pull on the negatively-charged electrons (and according to Newton's third law, "for every action, there is an equal but opposite reaction", this also causes the ions to move slightly towards the electrons at the cathode). Once the electrons return to the cathode, they are "reunited" with the ions, which are neutralized once again, and the process repeats. You probably ought to learn a little more about chemistry and how charges and ionized atoms work with each other before throwing out an argument against something that is saying the same thing as you are. Just saying

And if the electrons cannot move outside of the battery without ions moving inside the battery, then the ions are just as important.

Sure, they're just as important when it comes to making the battery actually work, but if someone is just trying to learn how current flows through a circuit, there is absolutely no need to tell them about how current flows just inside the battery.



Okay Nick, I've said my piece. Ratch can keep arguing all he wants, but I hope he can figure out from my posts where his assumptions are going wrong. I'll try not to respond to him anymore, and only to your questions.

Good luck

Best wishes,
Der Strom

 

[Ratchit]

Jon Wilder,

I reviewed this thread and found three posts by the OP. The first two were interrogatory, and the third was an observation. I believe that the first two were answered satisfactorily. The OP can ask again if he needs more help. The other not quite on topic messages can be ignored by those not interested. This forum in not set up to provide an electronics course, but instead to answer specific questions. As far as I can see, that has been done.

Ratch

 

[ljcox]

ljcox,

No, because then it would have units of joules (MKS) instead of joules/coulomb. Voltage is a density, not a unit of electrical potential energy.

See below.

Because of its potential energy, measured in joules (MKS).

Qualitatively yes, but a quantitive definition requires a per unit of time also.

Yes, I = dq/dt but that makes it a bit complicated for beginners.

Mathematically assumed to be positive to negative charge movement of a voltage source.

Movement of a voltage source???
Ratch

Yes, that is a point I had long forgotten.

So the term potential & potential difference is a little misleading.