Timeline for Capacitance for infinitely large plates
Current License: CC BY-SA 4.0
5 events
| when toggle format | what | by | license | comment | |
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| Jun 18, 2019 at 22:05 | comment | added | Hal Hollis | @user10796158, I'll see if I can find it, and I'll post a link if I do. | |
| Jun 18, 2019 at 22:04 | comment | added | Hal Hollis | @user10796158, (1) to be clear, a capacitor doesn't store electric charge. The charge $Q$ is the charge on one of the plates while the other plate has charge $-Q$ so a charged capacitor is not electrically charged, it is electrically neutral. However, a charged capacitor has stored energy (analogous to a charged battery). (2) Ordinarily, the capacitance of a capacitor is effectively constant so that we can write $i_C = \frac{dQ}{dt} = C\frac{dv_C}{dt}$ for electric circuits. There's a paper I read a while back that addresses some of the problems of taking this derivative when $C = C(t)$. | |
| Jun 18, 2019 at 3:08 | comment | added | An Ignorant Wanderer | Thank you for your answer. So this is kind of answering what I’m getting at, but not quite yet. I’m going to ask a related followup question if that’s okay. So capacitance tells us how much charge we can store for a given voltage. Say you have a capacitor, and you change the (small) distance between its (very large) plates. The capacitance will change. So really what’s the point of talking about ratio of charge to voltage for a given capacitor if it changes with distance? What is this change telling us about the capacitor? | |
| Jun 17, 2019 at 23:03 | history | edited | Hal Hollis | CC BY-SA 4.0 |
Added preface regarding infinite plates
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| Jun 17, 2019 at 21:49 | history | answered | Hal Hollis | CC BY-SA 4.0 |