Timeline for Does a Changing Electric Field Between The Plates of a Charging Capacitor Really Create a Magnetic Field?
Current License: CC BY-SA 4.0
7 events
| when toggle format | what | by | license | comment | |
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| Jul 31, 2018 at 22:51 | comment | added | Bob Jacobsen | @Brobin The B field due to the charging displacement current is around that current. And yes, despite your doubt, that’s how the world really works: we routinely show it in junior labs. | |
| Jul 31, 2018 at 15:39 | comment | added | Brobin | I think I am beginning to see your problem. Maxwell asserted that the displacement current had a magnetic field between the plates that had the same orientation as the charging current. As we have demonstrated the orientation (clockwise versus counterclockwise) is 180 degrees out of phase with the input currents field. | |
| Jul 31, 2018 at 12:18 | comment | added | Bob Jacobsen | @brobin. I think I’m not understanding your question. There’s also no displacement current once the electron flow is zero. Nowhere is there a contradiction with displacement current. | |
| Jul 31, 2018 at 12:10 | comment | added | Brobin | There is no way to generate a mag field once the electron flow has ceased. The capacitor is charged. Grasp the "up" electron flow on the first plate with the left hand. Your fingers will curl around and exit the space between the plates. Grasp the "down" current with left hand with the forefinger in the direction of electron flow. The fingers will again curl around to the space between the plates. The magnetic field is TWICE the field around the input wire. Or use the right hand for the conventional current. The answer will be the same. | |
| Jul 30, 2018 at 15:15 | comment | added | Bob Jacobsen | @Brobin True, but doesn’t effect this situation. If you look at the 3D shape of the capacitor, once current reaches the plates & spreads out there’s no way for it to generate a B field around the original direction. Only displacement current can do that. | |
| Jul 30, 2018 at 14:17 | comment | added | Brobin | Offhand not a bad answer but Ampere's Force Law states that anti parallel currents repel ,not cancel and thus we define the ampere as 2x10-7 newtons if the conductors are separated by one meter. | |
| Jul 29, 2018 at 3:25 | history | answered | Bob Jacobsen | CC BY-SA 4.0 |