Electron flow
- Thread starter sparks1
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hurk27
Senior Member
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- Portage, Indiana NEC: 2008
Re: Electron flow
Hey paul geuss what happens when they break the speed limit?
They get pulled over by the fuse.
Hey paul geuss what happens when they break the speed limit?
They get pulled over by the fuse.
sparks1
Senior Member
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- Massachusetts
Re: Electron flow
Secondly, if one 1 ampere = 1 coulomb or 6.25*10(18)power, how far will this quantity of electrons move in one foot if the voltage is 120 volts AC?
How slowly will one electron move can you give an example of this distance.
Secondly, if one 1 ampere = 1 coulomb or 6.25*10(18)power, how far will this quantity of electrons move in one foot if the voltage is 120 volts AC?
sparks1
Senior Member
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- Massachusetts
Re: Electron flow
Thanks.
This is the link I was looking for!
Thanks.
Re: Electron flow
1 Ampere is defined as a charge flow rate of 1 Coulomh/Second. or 0.6x10^18 electrons/second. This is a rate, not a big glob of electrons.
Now to answer your question, one would have to know the density of carriers in the wire and the size of the wire. The voltage is immaterial since you are specifying one Ampere.
Sparks, watch your units!
1 Ampere is defined as a charge flow rate of 1 Coulomh/Second. or 0.6x10^18 electrons/second. This is a rate, not a big glob of electrons.
Now to answer your question, one would have to know the density of carriers in the wire and the size of the wire. The voltage is immaterial since you are specifying one Ampere.
physis
Senior Member
Re: Electron flow
That is true Rattus. But if 1 amp is flowing then there has to be something carrying the charge past a point. I can't think of a way to get the charge of 6.25 x 10^18 electrons past a point without using electrons or protons to do it. And I don't think protons are moving.
- Location
- Lockport, IL
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- Semi-Retired Electrical Engineer
Re: Electron flow
I like your image showing a series of atoms, with electrons jumping from atom to atom along the wire. It is a very good image to explain the basics of current flow. But every analogy, by its very nature, will contain some false (which is to say, ?simplifying?) information. That is necessary to make the analogy easier to understand, and to give the learner a first look at what is happening. I was taking the discussion one level deeper into the realm of physics. By doing so, I am adding one level of complication to the learning experience.
The level I am adding is that the electron in the center atom is not really attracted to the atom to its left by the sudden appearance of a ?hole? (i.e., positively charged atom) in that direction. You are showing three atoms, and one electron from each atom moves to the left. What I submit for your consideration is that all three electrons felt a push at the same instant. The electron in the middle atom did not have to wait until the hole was created to its left, before it felt an attractive pull. Rather, it felt a push as soon as you close the switch to complete the circuit.
{ASIDE to Rattus: The semiconductor industry does not have a trademark claim on the word ?hole.? You are right to point out that the two different meanings should not be confused with each other. But the power industry has a right to use that word in our own chosen context.}
No. I am saying the neither the repulsive force between electrons within the same atom, nor the attractive force between the electrons and protons within the same atom, nor the repulsive force among all electrons that are in motion within the wire, are related to the cause of electron motion.
I like your image showing a series of atoms, with electrons jumping from atom to atom along the wire. It is a very good image to explain the basics of current flow. But every analogy, by its very nature, will contain some false (which is to say, ?simplifying?) information. That is necessary to make the analogy easier to understand, and to give the learner a first look at what is happening. I was taking the discussion one level deeper into the realm of physics. By doing so, I am adding one level of complication to the learning experience.
The level I am adding is that the electron in the center atom is not really attracted to the atom to its left by the sudden appearance of a ?hole? (i.e., positively charged atom) in that direction. You are showing three atoms, and one electron from each atom moves to the left. What I submit for your consideration is that all three electrons felt a push at the same instant. The electron in the middle atom did not have to wait until the hole was created to its left, before it felt an attractive pull. Rather, it felt a push as soon as you close the switch to complete the circuit.
{ASIDE to Rattus: The semiconductor industry does not have a trademark claim on the word ?hole.? You are right to point out that the two different meanings should not be confused with each other. But the power industry has a right to use that word in our own chosen context.}
bphgravity
Senior Member
- Location
- Florida
Re: Electron flow
Can anyone explain the exact physical reason electrons respond to magnetic fields, and in return create their own magnetic properties?
Can anyone explain the exact physical reason electrons respond to magnetic fields, and in return create their own magnetic properties?
Re: Electron flow
Charlie B., Of course, I merely said that Ed's analogy should not be confused with hole current in semicondutors. Neither should we say that conventional current is hole current as opposed to electron current. The mechanism is exactly the same for both electron and conventional current which represents a misunderstanding of current from the dark ages.
Charlie B., Of course, I merely said that Ed's analogy should not be confused with hole current in semicondutors. Neither should we say that conventional current is hole current as opposed to electron current. The mechanism is exactly the same for both electron and conventional current which represents a misunderstanding of current from the dark ages.
physis
Senior Member
Re: Electron flow
I might ask further if a motionless electron would respond to a magnetic field. And then ask how that motion may or may not be "relative" to a magnetic field.
Magnetism is a property of a charge in motion. The motion can be spin too. An electron responds to a magnetic field because the magnetism created by the electrons charge being in motion cannot be seperated from the electron.
I might ask further if a motionless electron would respond to a magnetic field. And then ask how that motion may or may not be "relative" to a magnetic field.
Re: Electron flow
I don't think this question has a simple answer--maybe no answer at all. There is a phenomenon called "force on a moving charge". The moving charge creates its own magnetic field which interacts with any external magnetic field. This phenomenon makes electric motors run, but I cannot explain it any further than that.
It is also the phenomenon employed in "Hall Effect" devices which are used in modern automotive distributors and in other sensors as well.
Yes Sam, the charge has to be moving.
I don't think this question has a simple answer--maybe no answer at all. There is a phenomenon called "force on a moving charge". The moving charge creates its own magnetic field which interacts with any external magnetic field. This phenomenon makes electric motors run, but I cannot explain it any further than that.
It is also the phenomenon employed in "Hall Effect" devices which are used in modern automotive distributors and in other sensors as well.
Yes Sam, the charge has to be moving.
sparks1
Senior Member
- Location
- Massachusetts
Re: Electron flow
1 Ampere is defined as a charge flow rate of 1 Coulomh/Second. or 0.6x10^18 electrons/second. This is a rate, not a big glob of electrons.
Thank you for that one rattus!
Now to answer your question, one would have to know the density of carriers in the wire and the size of the wire. The voltage is immaterial since you are specifying one Ampere. [/QB][/QUOTE]
How about 14-2 romex
1 Ampere is defined as a charge flow rate of 1 Coulomh/Second. or 0.6x10^18 electrons/second. This is a rate, not a big glob of electrons.
Thank you for that one rattus!
Now to answer your question, one would have to know the density of carriers in the wire and the size of the wire. The voltage is immaterial since you are specifying one Ampere. [/QB][/QUOTE]
How about 14-2 romex
sparks1
Senior Member
- Location
- Massachusetts
Re: Electron flow
I knew this topic would open up a can of worms!
[ February 23, 2005, 03:20 PM: Message edited by: sparks1 ]
I knew this topic would open up a can of worms!
[ February 23, 2005, 03:20 PM: Message edited by: sparks1 ]
sparks1
Senior Member
- Location
- Massachusetts
Re: Electron flow
http://hyperphysic.phy-astr.gsu.edu/hbase/electric/ohmmic.html
Rattus ,
here is the link for the electron density.
http://hyperphysic.phy-astr.gsu.edu/hbase/electric/ohmmic.html
Rattus ,
here is the link for the electron density.
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: Electron flow
Here is a short summary about ?fields?:
</font>
Here is a short summary about ?fields?:
</font>
- <font size="2" face="Verdana, Helvetica, sans-serif">The existence of a charge will create an electric field.</font>
- <font size="2" face="Verdana, Helvetica, sans-serif">A charge that is in the presence of an electric field, regardless of whether the charge is stationary or in motion, will feel a force ? it will be pushed by the field. The direction of the push will be in the same line (forward or backwards, depending on positive or negative charge) as the direction of the field.</font>
- <font size="2" face="Verdana, Helvetica, sans-serif">In addition to the above, when a charge is in motion, it will create around itself a magnetic field. This is the property that creates a magnetic field around a current-carrying wire.</font>
- <font size="2" face="Verdana, Helvetica, sans-serif">A charge in motion within a magnetic field (not a stationary charge) will feel a force ? it will be pushed by the field. The direction of the push will be at a right angle to the direction of the motion, and at a right angle to the direction of the field. This is the property that causes the rotor of a motor to get pushed in a circular path by the stator field.</font>
sparks1
Senior Member
- Location
- Massachusetts
Re: Electron flow
"electrons in metal do not hold still.
this movement is not a flow, it's more like a
vibration."
Interesting point, if there is no current the
the?electrons are still whizing around in some type of orbit!
So let us turn the circuit back on again for "current flow" .
Why do we use the term "current flow" when in fact it really doesn't flow very far at all.
The "real movement of energy"is created by the striking of the valence electrons. The result of this energy we know is given off as heat and measured in watts, but I don't mean watts.
It is this "real movement of energy" that is really moving.
This "real movement of energy" is more like the current speed I could get use to!
[ February 24, 2005, 10:31 AM: Message edited by: sparks1 ]
"electrons in metal do not hold still.
this movement is not a flow, it's more like a
vibration."
Interesting point, if there is no current the
the?electrons are still whizing around in some type of orbit!
So let us turn the circuit back on again for "current flow" .
Why do we use the term "current flow" when in fact it really doesn't flow very far at all.
The "real movement of energy"is created by the striking of the valence electrons. The result of this energy we know is given off as heat and measured in watts, but I don't mean watts.
It is this "real movement of energy" that is really moving.
This "real movement of energy" is more like the current speed I could get use to!
[ February 24, 2005, 10:31 AM: Message edited by: sparks1 ]
sparks1
Senior Member
- Location
- Massachusetts
Re: Electron flow
"The direction of the push will be at a right angle to the direction of the motion, and at a right angle to the direction of the field. This is the property that causes the rotor of a motor to get pushed in a circular path by the stator field."
This is Properly known as the Right Hand motor rule.
"The direction of the push will be at a right angle to the direction of the motion, and at a right angle to the direction of the field. This is the property that causes the rotor of a motor to get pushed in a circular path by the stator field."
This is Properly known as the Right Hand motor rule.
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