General > General Technical Chat
Electrons are round!
Simon:
--- Quote from: aetherist on August 14, 2023, 04:08:13 am ---
--- Quote from: TimFox on August 14, 2023, 03:33:06 am ---
--- Quote from: aetherist on August 14, 2023, 12:40:38 am ---
--- Quote from: TimFox on August 13, 2023, 11:46:45 pm ---Once again, if electricity “hugs the surface” of a wire, then why does the DC conductance (reciprocal of resistance) scale with the cross-sectional area, not the circumference?
--- End quote ---
Interesting -- are there good measurements?
On the other hand -- why are lightning down conductors often flat strap?
--- End quote ---
One of a myriad of sources for resistance of copper wire: do the math.
https://commons.wikimedia.org/wiki/File:Copper_cable_resistance.jpg
--- End quote ---
I did the math. That/there chart says that resistance decreases with radius R in a linear way.
The circumference of round wire increases in a linear R way with radius.
The area of a round wire increases in an RR way.
Hence area has nothing to do with resistance.
Circumference has everything to do with resistance.
--- End quote ---
I'll break the forum rules now and tell you that you are a fucking idiot! I don't know what math you are smoking but you are wrong. This is so basic that it is hard to explain to an idiot that will not listen!
the area of a circle is r^2*pi
the circumference is r*2*pi
Now if you were not an idiot you would spot the obvious! but you are a fucking idiot!!!
You should, if you were not a fucking idiot be able to see that the circumference will increase linearly with the radius while the area increases with the square. Maybe you would like to go down your local electrical store and buy different gauges of wire, then spend more money than you need to to learn basic physics and buy a milliohm meter, or buy so much of that wire in large gauges that it actually registers some ohms on a meter.
Now measure them and tell us your results.
WARNING: DO NOT post in this thread again until you come back with correct results. Failure to do so will result in instant banning!
DavidAlfa:
C'mon it's not that hard :-DD
Simon:
I'm referring to his claim that resistance is proportional to circumference rather than area. No I don't want his explanation, we know it will be bollocks! He has to prove it, in real life, the hard way. That's how scientists do it when they want to defy current understanding, unless of course you just messed up in your latest discovery of a super conductor!
aetherist:
--- Quote from: Simon on August 14, 2023, 06:14:55 am ---
--- Quote from: aetherist on August 14, 2023, 04:08:13 am ---
--- Quote from: TimFox on August 14, 2023, 03:33:06 am ---
--- Quote from: aetherist on August 14, 2023, 12:40:38 am ---
--- Quote from: TimFox on August 13, 2023, 11:46:45 pm ---Once again, if electricity “hugs the surface” of a wire, then why does the DC conductance (reciprocal of resistance) scale with the cross-sectional area, not the circumference?
--- End quote ---
Interesting -- are there good measurements?
On the other hand -- why are lightning down conductors often flat strap?
--- End quote ---
One of a myriad of sources for resistance of copper wire: do the math.
https://commons.wikimedia.org/wiki/File:Copper_cable_resistance.jpg
--- End quote ---
I did the math. That/there chart says that resistance decreases with radius R in a linear way.
The circumference of round wire increases in a linear R way with radius.
The area of a round wire increases in an RR way.
Hence area has nothing to do with resistance.
Circumference has everything to do with resistance.
--- End quote ---
I'll break the forum rules now and tell you that you are a fucking idiot! I don't know what math you are smoking but you are wrong. This is so basic that it is hard to explain to an idiot that will not listen!
the area of a circle is r^2*pi
the circumference is r*2*pi
Now if you were not an idiot you would spot the obvious! but you are a fucking idiot!!!
You should, if you were not a fucking idiot be able to see that the circumference will increase linearly with the radius while the area increases with the square. Maybe you would like to go down your local electrical store and buy different gauges of wire, then spend more money than you need to to learn basic physics and buy a milliohm meter, or buy so much of that wire in large gauges that it actually registers some ohms on a meter.
Now measure them and tell us your results.
WARNING: DO NOT post in this thread again until you come back with correct results. Failure to do so will result in instant banning!
--- End quote ---
Ok, i have the correct results. I got my results from the link provided by TimFox.
A 1.0 mm Cu wire 1000 m long has a resistance of 35 ohm
A 10.0 mm Cu wire 1000 m long has a resistance of 3.6 ohm.
A 10.0 mm wire has a Xsectional area 100 times that of a 1.0 mm wire.
Hence the resistance of a 10.0 mm wire should be 0.35 ohm based on Xsection area.
And the resistance of a 10.0 mm wire should be 3.5 ohm based on circumference.
So, my circumference theory has an "error" of 0.1 ohm.
But your area theory has an error of 3.15 ohm.
2N3055:
--- Quote from: aetherist on August 14, 2023, 07:30:56 am ---
--- Quote from: Simon on August 14, 2023, 06:14:55 am ---
--- Quote from: aetherist on August 14, 2023, 04:08:13 am ---
--- Quote from: TimFox on August 14, 2023, 03:33:06 am ---
--- Quote from: aetherist on August 14, 2023, 12:40:38 am ---
--- Quote from: TimFox on August 13, 2023, 11:46:45 pm ---Once again, if electricity “hugs the surface” of a wire, then why does the DC conductance (reciprocal of resistance) scale with the cross-sectional area, not the circumference?
--- End quote ---
Interesting -- are there good measurements?
On the other hand -- why are lightning down conductors often flat strap?
--- End quote ---
One of a myriad of sources for resistance of copper wire: do the math.
https://commons.wikimedia.org/wiki/File:Copper_cable_resistance.jpg
--- End quote ---
I did the math. That/there chart says that resistance decreases with radius R in a linear way.
The circumference of round wire increases in a linear R way with radius.
The area of a round wire increases in an RR way.
Hence area has nothing to do with resistance.
Circumference has everything to do with resistance.
--- End quote ---
I'll break the forum rules now and tell you that you are a fucking idiot! I don't know what math you are smoking but you are wrong. This is so basic that it is hard to explain to an idiot that will not listen!
the area of a circle is r^2*pi
the circumference is r*2*pi
Now if you were not an idiot you would spot the obvious! but you are a fucking idiot!!!
You should, if you were not a fucking idiot be able to see that the circumference will increase linearly with the radius while the area increases with the square. Maybe you would like to go down your local electrical store and buy different gauges of wire, then spend more money than you need to to learn basic physics and buy a milliohm meter, or buy so much of that wire in large gauges that it actually registers some ohms on a meter.
Now measure them and tell us your results.
WARNING: DO NOT post in this thread again until you come back with correct results. Failure to do so will result in instant banning!
--- End quote ---
Ok, i have the correct results. I got my results from the link provided by TimFox.
A 1.0 mm Cu wire 1000 m long has a resistance of 35 ohm
A 10.0 mm Cu wire 1000 m long has a resistance of 3.6 ohm.
A 10.0 mm wire has a Xsectional area 100 times that of a 1.0 mm wire.
Hence the resistance of a 10.0 mm wire should be 0.35 ohm based on Xsection area.
And the resistance of a 10.0 mm wire should be 3.5 ohm based on circumference.
So, my circumference theory has an "error" of 0.1 ohm.
But your area theory has an error of 3.15 ohm.
--- End quote ---
That table is simply wrong. Here is one that is correct:
https://www.engineeringtoolbox.com/copper-aluminum-conductor-resistance-d_1877.html
Resistance scales with cross section area. That is not some stupid theory, that is proven fact. If you don't trust scientists, follow the money.
Copper is sold by weight which is a cross section area x length x specific weight of copper. People would be VERY UNHAPPY with the price of cables if the current capacity was linear with diameter....
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