- #1

emeriska

- 17

- 0

## Homework Statement

We have an ordinary LRC circuit with inductance L, capacitance C and resistance R with an oscillating voltage with low frequency (U^e). Using the energy conservation law and Poynting's theorem, find the differential equation:

$$L \frac{\partial ^2}{\partial t^2}I + R \frac{\partial }{\partial t}I + L \frac{1}{C}I = \frac{\partial }{\partial t}U^e$$

## Homework Equations

I'll need to take advantage from the fact that I is defined as

$$I = \frac{\partial}{\partial t}q$$.

Knowing q is the charge.

## The Attempt at a Solution

Well, I've been looking around on the web to find something but I really can't find how to connect the Poynting theorem to that kind of circuit.

If any of you have some insights of a head start to give me that'd be great!