# RLC Understanding

1. May 9, 2014

### dwn

1. The problem statement, all variables and given/known data

Image

2. Relevant equations

Critical Damping

* related to '*' on image : diL/dt = -vc(0) - Ri(0)
When do we use this to solve for the other constant? In the text, an example problem is never fully explained in mathematical terms.

3. The attempt at a solution

I am looking for someone to kind of explain what to keep an eye out for when analyzing RLC circuits, or provide a source. I have looked through a couple different textbooks and certain things vary and its leading to confusion. One particular concern is after we calculate whether a circuit is over/under damped or critical (I know the characteristic equations for each), are we solving vc or iL. Now I'm sure it depends on what the question asks, but sometimes it includes both instances. Can someone please sort this out for me?

**EDIT**
The voltage for capacitor should be 12/5 = 2.4 Correct?

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Last edited: May 9, 2014
2. May 14, 2014

### rude man

Incorrect. What is the total resistance in series with L?

Also, your t(0+) diagram is wrong. The 1 ohm resistor has mysteriously migrated away from C!