# Multiple capacitor RC circuit

1. Feb 20, 2012

### jforce93

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

The circuit used in this problem is attached as an image. I made this in gEDA (the circuit is from the homework problem, I just didn't feel like using a scanner to get the image)
The 2-microfarad capacitor shown in the circuit attached is fully charged by closing switch S1 and keeping switch S2 open, thus connecting the capacitor to the 2,000 Volt power supply. At a later time, switch S1 is opened. Switch S2 is then closed. The 6-micro farad capacitor is initially uncharged. Determine the initial current in teh resistor the instant after switched S2 is closed.

2. Relevant equations

I = $\frac{-q0}{RC}$ e-t/RC (discharging a capacitor)
V = IR

3. The attempt at a solution

I'm not sure how to go about this, and I don't have an answer key. Should I calculate using the fact that the 2 micro farad capacitor is discharging, or the fact that the 6 microfarad capacitor is charing?
Thanks!

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

2. Relevant equations

3. The attempt at a solution
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

#### Attached Files:

• ###### circuit final.png
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Last edited: Feb 20, 2012
2. Feb 20, 2012

### jforce93

Sorry, forgot to attach a picture of the circuit. Will do that soon.

3. Feb 20, 2012

### Staff: Mentor

To find the initial current through the resistor, find the initial potential across that resistor. What are the initial voltages on the two capacitors at the instant S2 is closed?