- #1

laser

- 92

- 11

- Homework Statement
- Introduce a battery to an LR circuit

- Relevant Equations
- none

Let's say I have an LR circuit. I understand the mathematical derivation of this but would like to understand it conceptually.

Okay, so a battery is introduced (let's say 12 V). The inductor hates the change, so it induces 12 V in the opposite direction, opposing the battery.

So what happens then? IDK! My guess is that the two emfs cancel out, (which seems reasonable), and that means current is 0. Okay, fine, the book agrees with me. But what happens next? I know what is supposed to happen - the induced emf goes from 12 -> 0 in an exponential fashion. But I don't know *why*.

To me, it would seem reasonable for the induced emf to go to zero. Because di/dt = 0. But instead it decreases exponentially. So I must have a flaw in my understanding somewhere. Thanks!

Okay, so a battery is introduced (let's say 12 V). The inductor hates the change, so it induces 12 V in the opposite direction, opposing the battery.

So what happens then? IDK! My guess is that the two emfs cancel out, (which seems reasonable), and that means current is 0. Okay, fine, the book agrees with me. But what happens next? I know what is supposed to happen - the induced emf goes from 12 -> 0 in an exponential fashion. But I don't know *why*.

To me, it would seem reasonable for the induced emf to go to zero. Because di/dt = 0. But instead it decreases exponentially. So I must have a flaw in my understanding somewhere. Thanks!