Strange Posted December 24, 2019 Share Posted December 24, 2019 6 hours ago, westom said: Answers must be limited to misinformation 6 hours ago, westom said: I also ignored his silly belief that electricity is always same at both ends of a wire. You seem to be using “electricity” to mean voltage. And sometimes you seem to use it to mean current. And sometimes you mean static electricity/charges. No wonder you are so confused. 6 hours ago, westom said: Since one does not even know that a switched on or off DC source always results in AC currents at various frequencies. This may result in multiple frequencies but it doesn’t result in AC. Link to comment Share on other sites More sharing options...
swansont Posted December 24, 2019 Share Posted December 24, 2019 6 hours ago, westom said: Noted previously that superconductors still have some resistance. And then noted was, " Impedance (which is clearly not resistance) is a parameter at play." Superconductors change behavior when frequencies increase. No, you asserted this without evidence, contratry to the description of it, and ignored the discussion that supports the lack of resistance. 6 hours ago, westom said: Which is a transient discussion and really not relevant to static charges (also called static electricity) verses something completely different called a static electric discharges (also called electricity). It ties in with your mistaken claims surrounding electricity 6 hours ago, westom said: Static charges have an E field and no H field. Sure they do. Electrons and protons have intrinsic magnetic fields. There is no net field if the individual contributions cancel, and no field from charge motion, of course. But the individual charges have fields. Link to comment Share on other sites More sharing options...
Ghideon Posted December 25, 2019 Share Posted December 25, 2019 On 12/24/2019 at 5:33 AM, westom said: Now you are asking about some observer. Neither you nor I are relevant to two separate static charges and any motion between and relevant to those charges. (Unless you are asking about Schrodinger's cat which is irrelevant here). I asked since some observations and measurements of electrical phenomenons depend on frame of reference and observers' movements relative to charges . "Moving electric charges" does not state whether you are moving and the charge is stationary or if the charge is moving and you are stationery in some frame of reference. In science it is useful to have models* and definitions** that are consistent with that. *) In this case Maxwell and Special Relativity is enough as far as I know. Quantum mechanic related concepts such as Shrödinger's cat is not necessary. **) Again, in scientific discussions I prefer a definition such as Oxford: "Any effect resulting from the existence of stationary or moving electric charges." (https://www.oxfordreference.com/view/10.1093/oi/authority.20110803095745871) Link to comment Share on other sites More sharing options...
westom Posted December 27, 2019 Author Share Posted December 27, 2019 On 12/24/2019 at 5:51 AM, Strange said: You seem to be using “electricity” to mean voltage. And sometimes you seem to use it to mean current. And sometimes you mean static electricity/charges. The term "electricity" defines electricity. Voltage is only one parameter of electricity. Voltage is but one parameter that is different at two ends of a wire. You are expected to know that. A wire has electronic parameters. Parameters that mean electricity is never same at two ends of a wire. Switching electricity off and on DOES create AC currents. We would joke about the naive who somehow believed in pulsed DC currents. It exists when speculation rather than knowledge makes a conclusion. Apparently you do not know anything about the Fourier series. Please go learn this simple and relevant math before posting more empty and bogus denials. Had you first learned (from science or math), then you know that switching DC currents created AC currents. Those that do not become humor for the educated. Learn about Fourier Series. Then only reply. I expect is an attitude change from one of demeaning denials to one of curiosity and humility. -2 Link to comment Share on other sites More sharing options...
Strange Posted December 27, 2019 Share Posted December 27, 2019 4 hours ago, westom said: The term "electricity" defines electricity. Voltage is only one parameter of electricity. Voltage is but one parameter that is different at two ends of a wire. You are expected to know that. But you didn't say "voltage" is different at each end of a wire, you said "electricity" is different at each end of the wire. Which is meaningless. 4 hours ago, westom said: A wire has electronic parameters. "Electronic parameters"? 4 hours ago, westom said: Parameters that mean electricity is never same at two ends of a wire. You cannot measure or quantify electricity. You can measure voltage, which is what will be different at each end. The current should be the same. 4 hours ago, westom said: Switching electricity off and on DOES create AC currents. We would joke about the naive who somehow believed in pulsed DC currents. DC means always flowing in the same direction (pulsed or not). Let me support my case with (yet another) reference: Quote DC (direct current) is the unidirectional flow or movement of electric charge carriers (which are usually electrons). The intensity of the current can vary with time, but the general direction of movement stays the same at all times. As an adjective, the term DC is used in reference to voltage whose polarity never reverses. https://whatis.techtarget.com/definition/DC-direct-current But feel free to provide a reference to support your definition of DC. You have singularly failed to support any of your arguments with anything other than your imagination and attitude. 2 Link to comment Share on other sites More sharing options...
swansont Posted December 27, 2019 Share Posted December 27, 2019 4 hours ago, Strange said: But feel free to provide a reference to support your definition of DC. You have singularly failed to support any of your arguments with anything other than your imagination and attitude. Seconded. people in this thread have provided references and physical justifications. All you have given us is "Nuh uh" Link to comment Share on other sites More sharing options...
studiot Posted December 28, 2019 Share Posted December 28, 2019 On 12/23/2019 at 10:45 AM, studiot said: In particular I mentioned Maxwells's mesh theorem, since you like Maxwell. Are you aware of th special nature of the current in that theorem? Well I had a great Christmas in the home of both the DC electric battery and Superconducitivity. I see you have responded to others but not to my serious question about circuit theory. So let us stop beating about the bush, here is a small mesh which demonstrates the falsity fo both of your claims. For generality I have written complex impedences and AC generators, but the results are equally applicabl to DC meshes. I see Sensei has already dealt (mathematically) with some of your incorrct claims about DC electric circuits +1 So I have written The basic definition condition of the connecting wires for any network as my equation 1. This clearly asserts that The voltage at any point on a connecting wire in Circuit Theory is identical to the voltage at any other point on that same connecting wire. So that has dismissed your claim once and for all. Secondly note my equation 4 equally asserts that the mesh currrent in loop BDEFB is circulating with zero loop EMF Thus you have current but no voltage around the loop (although yhere are voltage differences bewteen certain points partway around the loop). This need not involve supeconductivity or any esoteric stuff, it is achieved with any old common or garden circuit elements. I am sure you ar familiar with the battery? So there you have voltage with no current, if the battery is not connected to anything. So let us have no more nonsense about Voltage with no current and current with no voltage. Link to comment Share on other sites More sharing options...
studiot Posted December 28, 2019 Share Posted December 28, 2019 (edited) In case my last example was too difficult here is a simpler one. I have formed two different circuits, using the same three circuit elements. In the first circuit switch SW1 has the entire circuit voltage across it but carries zero current. In the second circuit the same switch has zero voltage across it but carries the entire circuit currrent. Edited December 28, 2019 by studiot Link to comment Share on other sites More sharing options...
Phi for All Posted December 28, 2019 Share Posted December 28, 2019 On 12/26/2019 at 10:18 PM, westom said: The term "electricity" defines electricity. Voltage is only one parameter of electricity. Voltage is but one parameter that is different at two ends of a wire. You are expected to know that. A wire has electronic parameters. Parameters that mean electricity is never same at two ends of a wire. Switching electricity off and on DOES create AC currents. We would joke about the naive who somehow believed in pulsed DC currents. It exists when speculation rather than knowledge makes a conclusion. Apparently you do not know anything about the Fourier series. Please go learn this simple and relevant math before posting more empty and bogus denials. Had you first learned (from science or math), then you know that switching DC currents created AC currents. Those that do not become humor for the educated. Learn about Fourier Series. Then only reply. I expect is an attitude change from one of demeaning denials to one of curiosity and humility. ! Moderator Note westom, I was prepared to believe your training as an EE didn't require the same rigorous terminology that our physicists use, and that was the reason for the misunderstandings we've seen in this thread. But you continue to attack people rather than their ideas, and you seem to have a big chip on your shoulder about this. It's causing your posts to look unreasonable, full of preaching/soapboxing with no substance, no evidence to support your arguments. Others explain why they hold their stances, but you just wave your hands, and that doesn't work in a discussion. It makes you look like a troll just trying to get a negative reaction. It's possible to support your ideas without attacking people. Why don't you show how the Fourier series supports your ideas instead of using snide personal comments like "Apparently you do not know anything about the Fourier Series"? WE expect an attitude change from YOU, since you're the one arguing in bad form and failing to support your arguments. You've had three pages to express yourself, to persuade other members your ideas have merit, and you've wasted them so far. Please do more than insults and hand waiving. Link to comment Share on other sites More sharing options...
westom Posted December 29, 2019 Author Share Posted December 29, 2019 On 12/27/2019 at 4:15 AM, Strange said: "Electronic parameters"? You cannot measure or quantify electricity. You can measure voltage, which is what will be different at each end. The current should be the same. Please go learn the simple stuff. Yes electricity is always different at both ends of a wire. Start with something layman simple such as the Telegrapher's Equation. Because even wire is an electronic device. Link to comment Share on other sites More sharing options...
Ghideon Posted December 29, 2019 Share Posted December 29, 2019 (edited) 38 minutes ago, westom said: Please go learn the simple stuff. I think I did that. What I learned do not match your claims in this thread. 38 minutes ago, westom said: Yes electricity is always different at both ends of a wire. Within my profession a cable can have several different effects on for instance transmitted electrical signals. But electricity is always the same at both ends. We do not use different definitions or laws of physics at each end of a cable. It is one definition of electricity and a set of physical phenomenons and laws that when correctly applied* predicts an outcome for a specific situation. *) directly or indirectly through rules of thumb or diagrams/tables. Example: bandwidth vs length of CAT7 https://en.wikipedia.org/wiki/ISO/IEC_11801#CAT7 Edited December 29, 2019 by Ghideon added the reference Link to comment Share on other sites More sharing options...
westom Posted December 29, 2019 Author Share Posted December 29, 2019 On 12/28/2019 at 9:43 AM, Phi for All said: Why don't you show how the Fourier series supports your ideas instead of using snide personal comments like "Apparently you do not know anything about the Fourier Series"? BTW, I did explain that. Notice that Fourier Series was completely explained in one paragraph. Waveforms are simply a sum of sines and cosines - AC currents. Obviously turning on DC power (a step wave) is a sum of AC currents. Also noted: Fourier Series was even taught in high school math. And that the Pulsed DC is a popular joke among engineers. I am not going to write a chapter about Fourier Series. But if he wanted to learn, then he would have asked questions - not posted denials. He did not ask to understand how Fourier Series was relevant. He ignored how switched DC currents created the first radio communications because switched DC is AC currents. Instead, only posted were empty denials or comments that even completely ignored that reality. As if I do not know what I am talking about. I am not going to teach the entire chapter on Fourier Series. Especially when some clearly never get past the first few paragraphs. If he wanted to learn, then he stated what is relevant and why he does not understand that. No such comment was posted. Only more denials. One cannot explain this stuff to another who will not even ask what part of Fourier Series is relevant to the topic. In short, what I keep doing is challenging others to see why switching DC voltages creates AC currents. Even ignored and denied: that a static electric discharge creates radio and TV interference - AC currents. He did not ask to learn. Only argued from feeling - and not from how science works. 1 minute ago, Ghideon said: Within my profession a cable can have several different effects on for instance transmitted electrical signals. But electricity is always the same at both ends. Well that is a complete contradiction. Either cable has no effects on electricity. Or those effects means electricity is different at both ends of a wire. For example, we say the current in is same as current out - only in amperes. That current has phase changes. Its relationship to the other parameter that also describes electricity is changed. Telegrapher's equations makes that obvious. And does not include other relevant parameters including leakage currents. Electricity is never same at both ends of a wire. How much difference? Again, any denial must discuss the numbers - how much difference. It is always different. The statement insists that any denial must discuss numbers. If you know otherwise, then explain why the Telegrapher's equation exists - that explains, with parameters (numbers, how different electricity is as the other end. Link to comment Share on other sites More sharing options...
Ghideon Posted December 29, 2019 Share Posted December 29, 2019 (edited) 32 minutes ago, westom said: Or those effects means electricity is different at both ends of a wire. In your definition of electricity there might be a difference. Since you do not post supporting reference I checked https://en.wikipedia.org/wiki/Telegrapher's_equations : Quote The telegrapher's equations (or just telegraph equations) are a pair of coupled, linear partial differential equations that describe the voltage and current on an electrical transmission line with distance and time. The equations come from Oliver Heaviside who developed the transmission line model in the 1880s. The model demonstrates that the electromagnetic waves can be reflected on the wire, and that wave patterns can form along the line. ... The telegrapher's equations, like all other equations describing electrical phenomena, result from Maxwell's equations. The telegrapher's equations is a good example, covering several electrical phenomena that are related to my example of CAT7 network cables. But I can't find support for your claim that electricity is different at each end. (Numerous other aspects of signal transfer are of course different) Edited December 29, 2019 by Ghideon Link to comment Share on other sites More sharing options...
MigL Posted December 29, 2019 Share Posted December 29, 2019 Just because a certain model can be applied to a physical situation does not mean that model is applicable in ALL circumstances. A Fourier expansion models the square wave of a switch or diode as a combination of odd harmonics, and that is useful for analyzing certain behavior ( as does the wave behavior in the partial differential Telegraph equation for current AND voltage ), yet what is physically happening is that charge carriers are started and stopped from moving by a potential barrier or a gap. And since current is simply the rate of flow of charge carriers past a point ( or into and out of a region ), I don't see how applying a wave model clarifies the situation. And does not give justification for saying that starting stopping DC current is equivalent to AC current Link to comment Share on other sites More sharing options...
studiot Posted December 30, 2019 Share Posted December 30, 2019 (edited) On 12/28/2019 at 12:20 PM, studiot said: I see you have responded to others but not to my serious question about circuit theory. Well I am still waiting for some actual mathematics from you, as well as a response to my question. I have posted circuits and mathematics to which you also have not responded. On 12/28/2019 at 12:20 PM, studiot said: On 12/23/2019 at 10:45 AM, studiot said: In particular I mentioned Maxwells's mesh theorem, since you like Maxwell. Are you aware of th special nature of the current in that theorem? What do Fourier series the Telegraph equations (or their parent transmission line equations) have to do with Maxwell's Mesh Theorem? You cannot use the mesh currents in either FS or transmission equations as they are virtual currents. [aside for those who may be interested in the special nature of this method] Virtuality is their special nature, they are not the actual currents. Maxwell was a polymath in that he wrote extensive treatises in several areas, Mechanics, Thermodynamics as well as Electromagnetism. As such he was familiar with the 'virtual work or virtual displacement method' in Mechanics. The virtual displacement method pairs a set of real or actual forces with a set of imagined or virtual displacements in place of the actual displacements. This is done for ease of calculation and is permissible under the principle of superposition. This leads to solution of the forces, which in turn leads to solution of the actual displacements. The Maxwell Mesh Method is the electrical equivalent of this, pairing actual voltages with virtual currents, leading to solution of the actual voltages, in turn leading to solution of the actual currents. [/aside] Edited December 30, 2019 by studiot Link to comment Share on other sites More sharing options...
Strange Posted December 30, 2019 Share Posted December 30, 2019 14 hours ago, westom said: Please go learn the simple stuff. Yes electricity is always different at both ends of a wire. When you say "electricity is different at both ends" what device should I use to measure the "electricity" and what units is "electricity" measured in? Please provide authoritative references to support your answer. Link to comment Share on other sites More sharing options...
Phi for All Posted December 30, 2019 Share Posted December 30, 2019 17 hours ago, westom said: Please go learn the simple stuff. ! Moderator Note I'm so unimpressed with your efforts to discuss this subject civilly that I'm going to give you a three day vacation, and hopefully you'll reread some of the helpful posts trying to update your knowledge of electricity. Please lose the attitude, stop trolling for reactions, and realize that however well you THINK you're explaining yourself, it's failing categorically. A discussion is about persuading people with your arguments, and so far you're just a monkey throwing shit. Come back better. I'm going to ask everybody else to leave this thread alone while westom is suspended. Maybe the new year will bring new insights. 1 Link to comment Share on other sites More sharing options...
westom Posted January 4, 2020 Author Share Posted January 4, 2020 On 12/28/2019 at 8:30 AM, studiot said: In the first circuit switch SW1 has the entire circuit voltage across it but carries zero current. In the second circuit the same switch has zero voltage across it but carries the entire circuit currrent. You are just not getting it. Second of two pictures: a 'B' wire connects switch 1 to resistor 1. Since switch 1 is closed, a current is passing through that 'B' wire. That current means a voltage exists between the 'B' wire's switch 1 connection and its resistor 1 connection. If a voltage did not exist, then that wire has no impedance. No impedance means that 'B' wire can conduct infinite current and never burn out. It cannot. Wire always has impedance. Therefore that 'B' wire has a voltage where it connects to the switch. And clearly has a different voltage where it connects to a resistor. Since those voltages are different, then a voltage difference exist between both ends of the wire. Same applies to a previous mesh circuit. Those black lines are not perfect conductors. Ideal conductors never exist. Between every Z component is a conductor (an electronic part) that creates a voltage. Every closed switch and wire has impedance. That impedance is why every wire can only carry a limited current. And as current increases, voltages at both ends of that wire are more different. Second picture shows the switch closed. Caption reads "current no voltage". Impossible. Again, the voltage A-B exists. It is non-zero. It cannot possibly be zero. This is the simple stuff that was not learned. And so (Phil- stated because it is a fact without any insult, any emotion, or any trolling) the sentence said, "Please learn the simple stuff." Read the datasheet for any switch ever made. Even a closed switch has electronic parameters. One datasheet number is typically milliohms. Since milliohms of resistance exist in every switch, then a voltage A-B always exists across every switch. Is that voltage significant? Irrelevant to the fact. Does a voltage always exist across a closed switch that is conducting current? Of course. Always. So a voltage at both ends of that switch is always different. And therefore a voltage difference always exists across a switch - whether relevant or irrelevant. That is the point stated repeatedly. Same applies to every wire. Electrical parameters are always different at both ends of a wire. For the same reasons that a voltage difference always exists across every switch - if open, or if closed and conducting a current. I just don't get why this is so hard. studiot - you are not dealing with reality. You are trying to claim ideal circuit theory exists in the real world. To keep it simplified, we invent something that has never existed - the ideal conductor. In the real world, a voltage always exists at two ends of any wire or switch that is conducting electricity. In the real world, no ideal conductor exists. Only time that electricity can be same at both ends of a wire or switch? When it is not conducting electricity. Why is this simple stuff is so hard to grasp? Link to comment Share on other sites More sharing options...
Strange Posted January 4, 2020 Share Posted January 4, 2020 1 hour ago, westom said: Only time that electricity can be same at both ends of a wire or switch? Please define what you mean by "electricity" in that context, how it is measured and what units it is measured in. (I suspect most of the problems in this thread come from your misuse of English rather than any errors in electrical theory - on either side.) Link to comment Share on other sites More sharing options...
Sensei Posted January 4, 2020 Share Posted January 4, 2020 (edited) 4 hours ago, westom said: That impedance is why every wire can only carry a limited current. Nonsense. Heated metal melts and oxidize if there is present air with Oxygen 1. If you apply voltage counted in millions of volts, current passing through conductor unprepared (not designed) for such high voltages, will within milliseconds or microseconds reach melting temperature and burn wire breaking circuit. That happens in majority of electric and electronic devices. It is just a matter of applied voltage. e.g. fan is stopping working in computer power supply unit, which is transforming from 230 V/110 V AC to 12V/5V DC. It is starting giving larger voltage than it should e.g. 13-15 V, and motherboard, CPU and peripheral devices designed for 12V are damaged. Materials have various resistivity [Ohm*m]. Multiplied by area [m^2] of object and divided by length of object [m], gives resistance in Ohms. Conductors have very small resistivity thus very small resistance. Insulators have extremely large resistivity thus very large resistance. But neither resistivity nor resistance nor impedance is constant. It varies as a function of temperature and pressure. There are insulators that start conducting after heating them to the right temperatures under very large pressures. And there are conductors (at room temperature conductors!), which after cooling down to very low temperatures (below 90 K), become superconductors, as measured resistance is 0 (or close to 0). Drop of voltage on superconductor is indistinguishable from 0 V. Current passing throw conductor is heating it. As I mentioned earlier resistivity/resistance depends on temperature. Conductor which is heated due to electrons colliding with its atoms is worse resistor. Wire is also resistor. But with extremely low area and very large length 2) Heated metal melts and oxidize if there is present air with Oxygen1. 1) Therefor the first lightbulbs had vacuum, later replaced by inert gas at low pressure. 2) Imagine wire conductor with resistivity 1 ohm * m and 1 mm diameter and 1 meter long. R=p*A/l = 1 [ohm *m] * PI * (0.0005[m])^2 / 1[m] = 7.854e-7 ohm. Drop of voltage on such element will be extremely small. Heated metals expand, therefor cross-section area A, diameter and length of wire, will be changing as function of temperature. Edited January 4, 2020 by Sensei Link to comment Share on other sites More sharing options...
MigL Posted January 4, 2020 Share Posted January 4, 2020 The biggest problem here seems to be the lack of common definitions for the terms being used. What is 'electricity' at both ends of a wire ? And I believe that Studiot is aware that although we make certain 'assumptions' with circuit analysis, charge carriers move along a potential gradient. And, of course, a potential gradient implies different voltages along a wire. Without that gradient, charge carriers have no reason to move. To use the water analogy; Water will not flow in a horizontal pipe, but it will flow down an inclined pipe where gravity provides the gradient. Link to comment Share on other sites More sharing options...
westom Posted January 6, 2020 Author Share Posted January 6, 2020 On 1/4/2020 at 3:26 AM, Strange said: Please define what you mean by "electricity" in that context, how it is measured and what units it is measured in. Electricity is clearly the movement of electrons between two charges. That movement creates a large number of parameters including voltage, phase, an E filed, current, frequency, standing waves, an H field, and many other parameters. Electricity - a movement of charges across the Atlantic on a wire. What resulted is electricity on each end of that wire was different. The Telegrapher's equation was but one early example of how electricity is always different at both ends of a wire. So rather than argue, please explain why electricity is always same at both ends of a wire. List parameters that support your belief. Rather than just argue, instead, put up some facts. Quote ... with circuit analysis, charge carriers move along a potential gradient. And, of course, a potential gradient implies different voltages along a wire. Without that gradient, charge carriers have no reason to move. Another example of why we know electricity is always different at both ends of a wire. I suspect you do not know the different between longitudinal mode and transverse mode voltages. That also would explain why you do not grasp these concepts. On 1/4/2020 at 6:07 AM, Sensei said: Nonsense. Heated metal melts and oxidize if there is present air with Oxygen 1. Only nonsense is that conclusion. Put too much current through a wire (even in a vacuum) and it turns into plasma. No wire is an ideal conductor. Simplest science knowledge make that obvious. Quote Conductors have very small resistivity thus very small resistance. Insulators have extremely large resistivity thus very large resistance. Conductors have small resistance or large resistance. Insulators that have high resistance can also have low resistance. Examples of subjective (and therefore junk science) reasoning. "Large" and "small" says nothing useful without numbers. Meanwhile if it has high resistance or low resistance, electricity remains different at both ends. How does electricity travel through one of the best insulators - air? Insulating gases are still conductive. Just less so. No ideal conductor nor ideal insulator exists. Another basic electrical concept that remains unlearned. A thinnest wire can conduct 20,000 volts (ie static charges) and not be damaged. Voltage is an irrelevant (destructive) parameter. Another conclusion justified only by speculation and subjective rationalization. -2 Link to comment Share on other sites More sharing options...
Sensei Posted January 6, 2020 Share Posted January 6, 2020 (edited) 5 hours ago, westom said: Only nonsense is that conclusion. Put too much current through a wire (even in a vacuum) and it turns into plasma. No wire is an ideal conductor. Simplest science knowledge make that obvious. What states of matter do you know from physics lessons? Solid, liquid, gaseous and plasma. Wire is solid. But after heating it (by too large current) it melts. Heat it more and it will change state to gaseous. Heat it considerably more and it will change state to plasma. Sometimes, just sometimes, under special conditions of the environment (temperature and pressure), some state is skipped (e.g. sublimation). I don't know where you get idea that solid metallic wire turns immediately to plasma skipping two states of matter. Breakage happens in the weakest point of wire and immediately shutdowns current. Applying large current to melt metal is widely used method in metalurgy. Edited January 6, 2020 by Sensei Link to comment Share on other sites More sharing options...
Sensei Posted January 6, 2020 Share Posted January 6, 2020 7 hours ago, westom said: Conductors have small resistance or large resistance. Insulators that have high resistance can also have low resistance. Examples of subjective (and therefore junk science) reasoning. "Large" and "small" says nothing useful without numbers. To talk about numbers we would have to pick up specific materials to compare their exact properties. Here we have resistivity table of some example materials, conductors and insulators: 7 hours ago, westom said: How does electricity travel through one of the best insulators - air? Insulating gases are still conductive. Just less so. No ideal conductor nor ideal insulator exists. Air has at least 7.74*10^23 higher resistivity than Copper. My words still applies: Quote Conductors have very small resistivity thus very small resistance. Insulators have extremely large resistivity thus very large resistance. 7 hours ago, westom said: Another basic electrical concept that remains unlearned. Unclear for uneducated / improperly educated.. 7 hours ago, westom said: A thinnest wire can conduct 20,000 volts (ie static charges) and not be damaged. Voltage is an irrelevant (destructive) parameter. Another conclusion justified only by speculation and subjective rationalization. P = I * U E=Q * U Power dissipated by electrons passing through medium depends on current and voltage (voltage drop on element). Energy dissipated (...) depends on charges and voltage (drop). Charge Q divided by elementary charge e = 1.6021766*10^-19 C is quantity of electrons. In static electricity discharge, quantity of electrons (therefor Q and I as well) could be millions or billions times smaller than in typical electric or electronic device. e.g. P = 20,000 V * 10^-10 A = 0.00002 W Actually, in early XIX century, there was used technique to measure how much energy wire dissipated by placing it in water, and measuring temperature increase of water. Therefor calorie unit (1 calorie = energy needed to increase temperature of 1 gram of water by 1 C) has been introduced. https://en.wikipedia.org/wiki/Joule_heating "James Prescott Joule first published in December 1840, an abstract in the Proceedings of the Royal Society, suggesting that heat could be generated by an electrical current. Joule immersed a length of wire in a fixed mass of water and measured the temperature rise due to a known current flowing through the wire for a 30 minute period. By varying the current and the length of the wire he deduced that the heat produced was proportional to the square of the current multiplied by the electrical resistance of the immersed wire.[2]" As a result of very low power, very low energy, dissipated in very short time, on such wire with 20 kV, it does not melts, as melting temperature of metal is not reached fast enough. Give it constant 20,000 V, for seconds or minutes, and it will melt and break apart, disconnecting circuit.. That's how fuses work. https://en.wikipedia.org/wiki/Fuse_(electrical)#Thermal_fuses "In electronics and electrical engineering, a fuse is an electrical safety device that operates to provide overcurrent protection of an electrical circuit. Its essential component is a metal wire or strip that melts when too much current flows through it, thereby stopping or interrupting the current." (notice words on Wikipedia: metal wire melts) Link to comment Share on other sites More sharing options...
Strange Posted January 6, 2020 Share Posted January 6, 2020 9 hours ago, westom said: Electricity is clearly the movement of electrons between two charges. That movement creates a large number of parameters including voltage, phase, an E filed, current, frequency, standing waves, an H field, and many other parameters. Electricity - a movement of charges across the Atlantic on a wire. What resulted is electricity on each end of that wire was different. The Telegrapher's equation was but one early example of how electricity is always different at both ends of a wire. So rather than argue, please explain why electricity is always same at both ends of a wire. List parameters that support your belief. Rather than just argue, instead, put up some facts. Firstly, I notice that you have not answered my questions: I asked for how you would measure "electricity" at each end of the wire (not voltage, not current, not phase, not an electric field, but electricity) to demonstrate that it is different. You have not done that. Which is not surprising, because "electricity" is not a thing that can be measured, any more than "physics" or "history" can be measured. I have also asked you to provide references that support your use of the word electricity and you have totally failed to do that either (again, not surprising as your use of the word is idiosyncratic, to say the least). Quote Electricity is clearly the movement of electrons between two charges. So if I charge a capacitor, with an electric current and then isolate it so there is an electric voltage between the two terminals, there is no "electricity" by your definition because the electric charges are not moving through wires? That makes no sense. Quote Electricity - a movement of charges across the Atlantic on a wire. What resulted is electricity on each end of that wire was different. The movement of charges is current, not electricity. What differs at each end of the wire is voltage, not electricity. Quote So rather than argue, please explain why electricity is always same at both ends of a wire. List parameters that support your belief. If you say that "electricity is different at each end" it implies that things like the relationship between moving charges and current is different, or that Ohm's law is different. That somehow electricity behaves differently at each end. Quote Rather than just argue, instead, put up some facts. Here: Quote electricity /ˌɪlɛkˈtrɪsɪti,ˌɛlɛkˈtrɪsɪti,ˌiːlɛkˈtrɪsɪti/ noun 1. a form of energy resulting from the existence of charged particles (such as electrons or protons), either statically as an accumulation of charge or dynamically as a current. https://www.google.com/search?q=define+electricity It is about time you presented some support for your arguments, other than just bluster and insults. Do you realise that pretty much the ONLY reason that people are disagreeing with you is because of your inability to communicate in the English language? (That and your refusal to provide any support for your arguments, your refusal to answer questions and your general attitude.) 3 Link to comment Share on other sites More sharing options...
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