Electricity Discussion Thread

[turkey3_scratch]

I love electricity. Do you love electricity? Well, one of my hobbies and leisure time is spent studying electricity, learning more about it. Electricity is fascinating, for one thing because "electricity" is a term we use that has no standardized meaning. Open any book, any dictionary or website, and the definitions of electricity all differ. So if you think of it, electricity doesn't even exist!

Discuss electricity.

 

[turkey3_scratch]

Not sure if anyone will ever decide to join me in this discussion (sort of lonely here haha) but anyway, I think I've realized why so many people are confused about current. Current as a noun is different than current as a measurement. Current as a noun would be a flow of charge. A flow is a noun, so a flow of charge is a noun. Only problem is, current is measured in coulombs per second, which actually refers to the amount of charge passing any cross-sectional area in a circuit per second. So current as a measurement is a rate.

So, if we say "high current" it makes sense as a rate but not as a noun. How can you have a "high flow of charge"? You can have a high "rate of flow of charge" but not a high "flow of charge". Saying current is "fast" is better terminology because it fits both contexts. A flow of charge can be fast, and the amount of coulombs passing a cross-sectional area per second can also be fast. Or the rate of flow of charge can also be fast.

Perhaps if current didn't refer to both the flow of charge and the rate of the flow of charge, people would be less confused about current and would not have misconceptions that current is a "stuff" that when it is "high" there is more of it. When a current is fast or slow there is still the same amount of "stuff" which is charge; even when there is no current, the stuff is still there. It'd be better if we completely did away with the ampere and just stuck with coulombs per second. Too many people seem to ignore charge when it comes to current, which is very bad. When we stop thinking about charge, people can't understand these concepts.

 

[Ralston18]

My sense is that there is more confusion due to "Electron Flow Notation" vs "Conventional Flow Notation".

Just my thought at the moment......

 

[turkey3_scratch]

My sense is that there is more confusion due to "Electron Flow Notation" vs "Conventional Flow Notation".

Just my thought at the moment......

There's a good article you should read on that http://amasci.com/miscon/eleca.html#frkel it's actually a good thing.

 

[MrKrako]

Not sure if anyone will ever decide to join me in this discussion (sort of lonely here haha) but anyway, I think I've realized why so many people are confused about current. Current as a noun is different than current as a measurement. Current as a noun would be a flow of charge. A flow is a noun, so a flow of charge is a noun. Only problem is, current is measured in coulombs per second, which actually refers to the amount of charge passing any cross-sectional area in a circuit per second. So current as a measurement is a rate.

So, if we say "high current" it makes sense as a rate but not as a noun. How can you have a "high flow of charge"? You can have a high "rate of flow of charge" but not a high "flow of charge". Saying current is "fast" is better terminology because it fits both contexts. A flow of charge can be fast, and the amount of coulombs passing a cross-sectional area per second can also be fast. Or the rate of flow of charge can also be fast.

Perhaps if current didn't refer to both the flow of charge and the rate of the flow of charge, people would be less confused about current and would not have misconceptions that current is a "stuff" that when it is "high" there is more of it. When a current is fast or slow there is still the same amount of "stuff" which is charge; even when there is no current, the stuff is still there. It'd be better if we completely did away with the ampere and just stuck with coulombs per second. Too many people seem to ignore charge when it comes to current, which is very bad. When we stop thinking about charge, people can't understand these concepts.

In my opinion, fast wouldn't be a better choice. I mean, the speed of the electron flowing is not going to change at all. What changes is the amount of electrons that passes a section. I don't really thing there is a misconception with high current. I'm not really sure if i got your point.

By the way, i think the most misconception i have encountered yet is the tension-current mistake. At least in spanish, a lot of people get confused with both terms and it is really frustrating. I think is more due to a lack knowledge in the field that any other thing.

 

[turkey3_scratch]

Yes when the speed increases more pass a section per second. Also, it's not always electrons. If you touch both pins of an AC outlet and get shocked, potassium and chloride ions are flowing in your body. They are the charge. Protons can also flow in substances like salt water.

 

[Pinhedd]

Not sure if anyone will ever decide to join me in this discussion (sort of lonely here haha) but anyway, I think I've realized why so many people are confused about current. Current as a noun is different than current as a measurement. Current as a noun would be a flow of charge. A flow is a noun, so a flow of charge is a noun. Only problem is, current is measured in coulombs per second, which actually refers to the amount of charge passing any cross-sectional area in a circuit per second. So current as a measurement is a rate.

So, if we say "high current" it makes sense as a rate but not as a noun. How can you have a "high flow of charge"? You can have a high "rate of flow of charge" but not a high "flow of charge". Saying current is "fast" is better terminology because it fits both contexts. A flow of charge can be fast, and the amount of coulombs passing a cross-sectional area per second can also be fast. Or the rate of flow of charge can also be fast.

Perhaps if current didn't refer to both the flow of charge and the rate of the flow of charge, people would be less confused about current and would not have misconceptions that current is a "stuff" that when it is "high" there is more of it. When a current is fast or slow there is still the same amount of "stuff" which is charge; even when there is no current, the stuff is still there. It'd be better if we completely did away with the ampere and just stuck with coulombs per second. Too many people seem to ignore charge when it comes to current, which is very bad. When we stop thinking about charge, people can't understand these concepts.

I think that you're driving yourself into confusion by attempting to frame scientific definitions in terms of language grammar. Electromagnetics is a field of science, not language arts.

Charge, measured in coulombs, is defined as the number of charges on a one farad capacitor with a potential of one volt between the plates.

Current, measured in amperes, is defined as the time rate of change of charge. It is the time-domain derivative of charge. An average of one ampere over a period of one second yields one coulomb of charge.

Current density, measured in amperes per square meter is the spatial-domain derivative of current. This is relevant to material analysis and won't be seen in a circuit topology anymore than resistivity would be seen in a circuit topology.

One thing that may confuse you a bit, and I would not be surprised if it did because it's not taught at all outside of electrical and computer engineering classes, is the relationship between the electric field and electric current.

Electrons moves very, very quickly. However, they spend the vast majority of their time zipping around the atoms to which they are bound or locally within a conductive lattice such as a metal. This natural movement is due to the thermal excitation of the material. When an electron is placed in an electric field, that field exerts a force (measured in newtons) on the electron, which causes it to have some net velocity. This net velocity is called the drift velocity.

The drift velocity of electrons is a function of material properties and the strength of the electric field. I'll let you look up some specific examples, but I will tell you that it is very, very low. A typical drift velocity for electrons in a one ampere current through a narrow wire at low voltage is in the range of micrometers per second.

By comparison, electric fields propagate very, very quickly. In free space, the propagation rate of an electric field is C, or the speed of light. This is because the electric field modulator is the photon.

In an unshielded conductive medium such as a pair of twisted copper wires, the propagation rate is around 0.97C, or just below the speed of light. In a shielded conductive medium such as a coaxial cable, the propagation rate is around (2/3)C, or two-thirds of the speed of light.

The electric force caused by the electric field or magnetic induction causes energy to be transferred rapidly from one charge carrier to another through repulsion. Thus, while each charge carrier drifts very, very slowly, the information carried by the field propagates very, very quickly.

If you're interested in this stuff, shoot me a PM.

 

[turkey3_scratch]

An electron can be inside an electric field, though, even if it's not drifting, right? Or is the drift just so small it's negligible? Electric fields connect every charge in the universe, and not all have a net velocity of drift, or do they?

For example, when there is a charge imbalance from two dissimilar insulators coming into contact, there would be a separation of charge and also a strong electric field, but the charge would not flow until it is discharged, right?

 

[Pinhedd]

An electron can be inside an electric field, though, even if it's not drifting, right? Or is the drift just so small it's negligible? Electric fields connect every charge in the universe, and not all have a net velocity of drift, or do they?

For example, when there is a charge imbalance from two dissimilar insulators coming into contact, there would be a separation of charge and also a strong electric field, but the charge would not flow until it is discharged, right?

Correct. The E field is defined at all points in space.

Consider a small length of copper wire placed inside of a uniform time-invariant electric field that is contained in a vacuum. The lorentz force acts upon all charged particles contained within the copper wire. The electrons, being highly mobile, will rearrange themselves until the force acting on the electrons from the E field is neutralized by the repulsion force acting on the electrons from electrons of like spin.

The electrons will still be subject to the force from the E field, but they will have nowhere to move. If the E field is made to be time-variant, the electrons can be yanked back and forth, heating up the copper wire. This is what occurs inside of a microwave oven.

 

[turkey3_scratch]

So you're saying an electric field can affect objects stuck in the middle of it, not just the objects the field is between? I guess what I'm trying to say is, does an electric field only exist between individually charged particles, or can a collective group of charges have one uniform electric field with another collective group of oppositely charged charges? And if the latter is true, then charge shoved between those two collective groups is affected?

 

[Pinhedd]

So you're saying an electric field can affect objects stuck in the middle of it, not just the objects the field is between? I guess what I'm trying to say is, does an electric field only exist between individually charged particles, or can a collective group of charges have one uniform electric field with another collective group of oppositely charged charges? And if the latter is true, then charge shoved between those two collective groups is affected?

Each and every charged particle in the universe generates its own electric field. Electrically neutral atoms will have equal numbers of particles of opposite charge, which more or less cancels the field around that atom out.

Consider as an example, Hydonium, or a Hydrogen ion. A single proton with a single electron in its orbit. A proton is not an elementary particle, it is comprised of two up quarks and a single down quark. An up quark has an electric charge of +2/3e and a down quark has an electric charge of -1/3e. This adds up to exactly +1e for a proton. An electron has an electric charge of -1e. The electric field of the proton and the electron more or less cancel eachother out.

The electric field is a vector field that is defined at all points in space. The principle of superposition means that each particle contributes to the magnitude and direction of the field at all points in space. However, the field does not propagate instantly, so this can complicate things a bit.

 

[4Ryan6]

I love electricity. Do you love electricity? Well, one of my hobbies and leisure time is spent studying electricity, learning more about it. Electricity is fascinating, for one thing because "electricity" is a term we use that has no standardized meaning. Open any book, any dictionary or website, and the definitions of electricity all differ. So if you think of it, electricity doesn't even exist!

Discuss electricity.

Electricity is marvelous and understanding how it exists is mind expanding, but making electricity work for you is applying it, you can see the raw power of electricity in a bolt of lightning, and if you could harness, store, and use that free electrical power, you could change the world.

But Sir, there are many established corporations out there that want things to stay exactly the way they are, because they are profiting from the way things are, and they do not want their profits hindered, and there is no line they won't cross to keep things as they are.

You should look for any information you can get your hands on that was written by Nikola Tesla, he was also fascinated by electricity and was cheated out of being able to bring some of his best ideas to reality.

He was a genius way ahead of his day and if you seek out some of his works I think you will find the answers you seek.

 

[MU_Engineer]

Electricity is interesting. Computers use DC logic, which at least in my experience is much easier to understand compared to AC circuits. To me, AC is more interesting as it is the kind of electricity that represents nearly all electrical distribution and usage (the small amount of HVDC transmission notwithstanding.) It also doesn't help that one of my other hobbies is woodworking and old industrial machinery which invariably runs on 3-phase AC (and often 440/480 volts) is the Holy Grail of equipment.

 

[turkey3_scratch]

I have a book called AC DC the First Standards War or something. I need to get back to reading it.

 

[Ralston18]

Electricity is fascinating - agreed. However the very much related magnetism is even more fascinating to me.....

Some of the newer magnets are very small and very strong. A younger family member actually got himself paInfully pinched between magnets.

North-South, Positive-Negative. Electricity creating magnets. Magnets creating electricity. Very interesting world.

 

[turkey3_scratch]

Electricity is fascinating - agreed. However the very much related magnetism is even more fascinating to me.....

Some of the newer magnets are very small and very strong. A younger family member actually got himself paInfully pinched between magnets.

North-South, Positive-Negative. Electricity creating magnets. Magnets creating electricity. Very interesting world.

Magnets don't create electricity, though. For one thing, "electricity" is really not anything that is defined. Some authors go as far as saying it does not exist since there is no definition on what it is http://amasci.com/miscon/whatis.html

What exactly are you referring to by "electricity"? I'm assuming you're talking more about electric fields. I know a flow of electric charge creates magnetic fields. That's what current does. Current + voltage = power = rate at which energy is transferred (energy being electric and magnetic fields in this case).

 

[Ralston18]

Yes. Very much the classic nail wrapped in wire carrying an electrical current sort of magnet.... (Electromagnet).

But also just the lodestone magnet up to today's button size super magnets. Sans any current carrying wires.

What about the current created by a wire spinning in a magnetic field? Classic generator/alternator. But I think I understand or at least still remember energy is neither created or destroyed - only transformed. No argument there.

Sort of at the point in my life where I now just marvel at it all....

However, I will carry a magnet in my hand but I will not stick my hand in an electrical outlet.

 

[turkey3_scratch]

I mean, you can stick it into ground, I don't think that'll cause a problem, right?

 

[Ralston18]

Unfortunately I have had some bad luck with bad, ungrounded outlets....

And as a kid I remember people taking the "hot" and "neutral" wires (as I now know them) via an electrical extension cord and attaching each respective wire to its own metal rod. The rods would be placed some distance apart in a well watered lawn at night. When the extension cord was plugged the end result was night crawlers popping up on the surface to avoid the "zapping". The theory being you could get fish bait without digging up the front yard. Not a process I care to validate. My worms have a happy life, albeit brief sometimes, in my compost pile.

Digression aside: Anyway, AC DC the First Standards War sounds interesting. Author? Thanks.

 

[turkey3_scratch]

Unfortunately I have had some bad luck with bad, ungrounded outlets....

And as a kid I remember people taking the "hot" and "neutral" wires (as I now know them) via an electrical extension cord and attaching each respective wire to its own metal rod. The rods would be placed some distance apart in a well watered lawn at night. When the extension cord was plugged the end result was night crawlers popping up on the surface to avoid the "zapping". The theory being you could get fish bait without digging up the front yard. Not a process I care to validate. My worms have a happy life, albeit brief sometimes, in my compost pile.

Digression aside: Anyway, AC DC the First Standards War sounds interesting. Author? Thanks.

https://www.amazon.com/AC-DC-Savage-First-Standards-ebook/dp/B008NBZ2ZG?ie=UTF8&*Version*=1&*entries*=0

It seems most electrical standards are founded on people and their greed for money.

"A fascinating history of the battle that decided what comes through the wires when we flick a switch. A great story of how far people will go to prove they're right." - J.J. Yore

 

[Ralston18]

Thank you. Just placed the book on hold via our public library website. And by merely "inconveniencing" (as I once read) a few zillion electrons.

Unfortunately the battle for standards in many areas is still being established probably in much the same way via lobbyists, campaign contributions, and targeted regulations/laws. But those discussions are for another forum I think.

 

[JamesGoblin]

I remember one of my professors confusing us with his favorite "Electricity? But you can't even define it!". There was some truth in his words thou!?