# Homework Help: RC circuit voltage

1. Feb 16, 2012

### likephysics

1. The problem statement, all variables and given/known data
Find Vn in the attached ckt.

2. Relevant equations

3. The attempt at a solution
C12 & C2G act as capacitive voltage dividers. But I don't know how to account for R in parallel with C2G.

#### Attached Files:

• ###### ckt.png
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2. Feb 16, 2012

### Antiphon

There are at least three mathematically distinct approaches to solving this. What technique are you supposed to use?

3. Feb 16, 2012

### likephysics

Any technique that works.
I'd prefer KVL.

4. Feb 17, 2012

### likephysics

Anyone?

5. Feb 17, 2012

### Staff: Mentor

If V1 is an ideal source, then C1g is irrelevant (except for the added current it will draw from the voltage source, it won't have any effect on the voltage delivered to the remainder of the circuit).

Why not remove the load resistor and determine the Thevenin equivalent of the rest? When you then add back the load you'll have a voltage supply and RC voltage divider to analyze (note that the Thevenin voltage will be frequency dependent unless V1 has a given fixed frequency).

6. Feb 18, 2012

### likephysics

Thanks. I got it. It's so simple, if C1g is ignored.