regards my question is how each coulomb of charge can lose (transfer ) energy when going from a to b when electrons are very slow

the definition of potential difference: is how much each coulomb of the charge loses (transfer ) energy when going from a to b

an example to clarify the question

we have a wire from the beginning to the end of the wire (point a point b ) the potential difference is 1 v so how then coulomb of charge cen go from a to b and transfer that energy when electrons are very slow

 

The electrons are "slow" .....but they bump into one another.

 

Yes. electrons are "slow". Thats why it takes Windows so long to boot up!

 

regards my question is how each coulomb of charge can lose (transfer ) energy when going from a to b when electrons are very slow

the definition of potential difference: is how much each coulomb of the charge loses (transfer ) energy when going from a to b

an example to clarify the question

we have a wire from the beginning to the end of the wire (point a point b ) the potential difference is 1 v so how then coulomb of charge cen go from a to b and transfer that energy when electrons are very slow

Think of a pipe full of water. As soon as you push more water into one end of the pipe, some comes out of the other end.

Same as electrons of the copper wire. As soon as you try to push some into one end of the wire, copper wire will give up electrons on the other end of the wire to prevent charge from building up on the wire. If copper wire kept the charge until the new electrons got to the other end, the positive wire would have a strong electrostatic attraction to the negative wire (but it doesn't so you realize that the "goesinta" equals the "goesotta").

PS. Could you imagine having to wait for water coming from the bottom of the well each time you turn on your faucet? Or, coming from the community water treatment plant? You don't have to wait for electrons coming all the way from the battery either.

 

Yes. electrons are "slow". Thats why it takes Windows so long to boot up!

Open a second Windows on the other side of the house to get cross ventilation - it speeds things up.

 

regards my question is how each coulomb of charge can lose (transfer ) energy when going from a to b when electrons are very slow

the definition of potential difference: is how much each coulomb of the charge loses (transfer ) energy when going from a to b

an example to clarify the question

we have a wire from the beginning to the end of the wire (point a point b ) the potential difference is 1 v so how then coulomb of charge cen go from a to b and transfer that energy when electrons are very slow

Coulombs don't transfer electrical energy because Electric Current is not a flow of electrical energy.

http://amasci.com/miscon/energ1.html

If electricity is like water inside a pipe, that's the Hydraulic Analogy. But water is not a form of energy. In hydraulics, the energy travels instantly to all parts of the fluid loop, while the fluid itself moves slowly. Two things are flowing through the pipe: slow fluid and fast energy. Electricity is like the fluid. Not like energy.

 

Electric current is charge/time, i.e. ampere = coulomb per second,
or ampere x second = coulomb

It takes energy to move the charge through a potential difference. The amount of energy = charge x voltage.

Let us examine the units of charge, current, power, and energy.

Power = ampere x volt = watt
Energy = power x time = amp x volt x second
Charge = coulomb = amp x second

hence,

Energy = coulomb x volt

 

regards my question is how each coulomb of charge can lose (transfer ) energy when going from a to b when electrons are very slow

the definition of potential difference: is how much each coulomb of the charge loses (transfer ) energy when going from a to b

an example to clarify the question

we have a wire from the beginning to the end of the wire (point a point b ) the potential difference is 1 v so how then coulomb of charge cen go from a to b and transfer that energy when electrons are very slow

Yep....the actual "electron drift" is actually just a few inches per hour in a copper wire with an amp flowing through it...while the energy transfer is just below the speed of light. In an electron tube, however, the actual electron drift is MUCH faster....approaching relativistic speeds in tubes like Klystrons.

 

Coulombs don't transfer electrical energy because Electric Current is not a flow of electrical energy.

http://amasci.com/miscon/energ1.html

That link is so bad at making its point that I see it as a strong support for this aspect of the water analogy. It makes not one compelling argument why a coulomb in a wire is different than a slug of water in a pipe.

 

We try to use analogs of mass flow when we explain current flow. Think of it as more of a current or charge alignment. When all the little electric and magnetic fields line up......it can ripple or wiggle an impulse(change in alignment) at super duper speeds.

 

That link is so bad at making its point that I see it as a strong support for this aspect of the water analogy. It makes not one compelling argument why a coulomb in a wire is different than a slug of water in a pipe.

I think you misread his points, badly.

A coulomb in a wire is similar to a slug of water in a pipe in the basic separation of flow of matter and flow of energy. The water is the medium for energy transfer, that slug of water is not the energy itself. In a closed loop water system much like a DC current loop the media just moves round the loop but energy flows one way. The misinterpretation of the water analogy equates the water flow as energy with the KE in the mass of the medium instead of pressure in a fluid IMO.

 

The misinterpretation of the water analogy equates the water flow as energy with the KE in the mass of the medium instead of pressure in a fluid IMO.

Ah, I see. Interesting. As a chemical engineer, I think about pressure and pressure drops, almost never kinetic energy. In fact that never occurred to me in this discussion. Yeah, KE is not a good part of the analogy.

 

Kinetic energy of water is a good approximation of electrical inductance.

 

Kinetic energy of water is a good approximation of electrical inductance.

I can see an analogy between the KE of water in a column and the magnetic component energy of the electrical energy of the circuit mathematically but not physically. We can mistakenly pretend the electrical KE is in the physical mass of the charge carriers in a simple DC circuit using the gravitational open loop water analogy but it's usefulness is very limited in the understanding of real electrical circuits that use inductance like transformers.

 

I don´t understand why open loop? Mass of water behaves just like inductance when in a closed system, see water hammer for instance. Also I specifically said inductance, not induction because that is a different matter and is not as easy to pull off.

 

I don´t understand why open loop? Mass of water behaves just like inductance when in a closed system, see water hammer for instance. Also I specifically said inductance, not induction because that is a different matter and is not as easy to pull off.

Drawing a parallel between a decoupling cap and a water hammer arrester was one of my early "aha!" moments when things got a little less confusing for me.

I know none of these analogies are perfect, but they certainly can be helpful sometimes. I'm not always sure I'm following the water/gravity analogies, but closed loop water analogies have helped me a lot as I've tried to wrap my head around the crazy world of electronics.

 

I don´t understand why open loop? Mass of water behaves just like inductance when in a closed system, see water hammer for instance. Also I specifically said inductance, not induction because that is a different matter and is not as easy to pull off.

The main reason I say that is typically we model inductance/inductors in that analogy with external devices and not use the media, like this where the driving force is water pressure in a closed loop and/or gravity in a open loop. IMO to equate the mass of water directly to inductance is a poor physical analogy either way.

https://ece.uwaterloo.ca/~dwharder/Analogy/Inductors/

Initially, as the water wheel has mass, it does not turn (that is, it opposes the force of the pump). However, the force slowly begins to cause the wheel to turn and soon the wheel is turning at a rate equal to the flow of the water, as is shown in Figure 2. If the water is not moving, the water wheel will oppose any flow. If the water wheel is moving, it will resist any change to the flow. If the power to the pump is turned off, the water wheel will continue to turn.

https://www.allaboutcircuits.com/technical-articles/understanding-electricity-with-hydrodynamics/

An inductor is also very easy to compare, and if you've ever seen a water mill operating it'll be even easier. The inductor is like the wheel being propelled by the moving water; it will resist an initial flow or any change in flow once it is already turning at a steady rate.

The pressure wave that causes water hammer uses water as the medium of energy transfer.