Timeline for Birds on a wire (again) - how is it that birds feel no current? They are just making a parallel circuit, no?
Current License: CC BY-SA 4.0
15 events
| when toggle format | what | by | license | comment | |
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| Mar 30, 2020 at 0:08 | comment | added | Clonkex | @user2705196 I have to confess I still don't understand. If the wire is assumed to have 0 resistance, surely all current would flow through this hypothetical ideal wire and the bird with have 0 potential across its legs. | |
| Mar 29, 2020 at 23:22 | comment | added | user2705196 | en.m.wikipedia.org/wiki/Node_(circuits) | |
| Mar 29, 2020 at 23:19 | comment | added | user2705196 | @Clonkex I see! Sorry, I should have clarified this differently. These circuit diagrams actually have a technical meaning. All wires have zero resistance. And thus anything that is connected with just wires in these diagrams must be at the same electric potential. And that's the source of this confusion. The potential needs to somehow drop in the circuit. There must be another resistor. This is not just nitpicking but goes to the very hard of what an electrical potential is! | |
| Mar 29, 2020 at 22:31 | comment | added | Clonkex | @user2705196 I don't see how the diagram is wrong. It's showing a 600V voltage source, but it's not showing it across the bird's legs. Do you realise the bird is represented by the 1MΩ resistor? It's in parallel with a very high resistance compared to the wire, which means the voltage potential across the bird's legs is incredibly small. | |
| Mar 29, 2020 at 21:57 | comment | added | user2705196 | @Clonkex The fact that a potential difference drives a current is at the heart of the OP's confusion. Because this diagram is wrong you can read it as there being a 600V potential difference between the bird's legs. This is exactly the problem. (Because if the source voltage emf was the actual voltage difference between the bird's legs the current would indeed be enormous.) | |
| Mar 29, 2020 at 3:58 | comment | added | Clonkex | @user2705196 Obviously it's just meant to indicate a 600V voltage source. | |
| Mar 28, 2020 at 11:22 | comment | added | Peter - Reinstate Monica | @Džuris That would be the correct depiction (although the resistance of a high-current overhead cable is more like 1E-6 Ohm/10cm). I created a diagram like that in my answer. | |
| Mar 27, 2020 at 21:05 | comment | added | user2705196 | The circuit diagram makes no sense. The diagram simultaneously shows that the two ends of the battery have the same potential and that there is a 600V potential difference. That cannot be. | |
| Mar 27, 2020 at 18:29 | comment | added | Itsme2003 | The diagram is fundamentally flawed. There should be an additional resistor shown on the bottom wire with a value such as 2 ohms to limit the current flowing through the circuit. Otherwise, the wires would melt. | |
| Mar 27, 2020 at 12:27 | comment | added | Džuris | To respond to OP's confusion of parallel circuits, you could include 62 milliohm resistance in parallel with the megaohm one and observe all the current flowing through the wire and almost nothing through the bird. | |
| Mar 27, 2020 at 11:43 | comment | added | toolforger | Actually it is a parallel circuit. It's just that the wire has a much lower resistance than the bird, so the bird is getting very little current (not zero but probably below all sensory thresholds). | |
| S Mar 27, 2020 at 9:38 | history | suggested | Glorfindel | CC BY-SA 4.0 |
typos corrected
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| Mar 27, 2020 at 9:07 | review | Suggested edits | |||
| S Mar 27, 2020 at 9:38 | |||||
| Mar 26, 2020 at 13:50 | review | First posts | |||
| Mar 26, 2020 at 15:55 | |||||
| Mar 26, 2020 at 13:48 | history | answered | Philip.P | CC BY-SA 4.0 |