# Calculating charge on a capacitor in a DC circuit

1. ### dancavallaro

13
1. The problem statement, all variables and given/known data
See attached image for a circuit diagram. The assumptions are that transients have died out and the currents and charges have reached their equilibrium values. I have to calculate the charge on the capacitor.

2. Relevant equations
$$Q_C = C \Delta V$$
$$V_C(t) = Q(t)/C = V_0(1-e^{-t/RC})$$

3. The attempt at a solution
I honestly am not really sure where to start with this. Given the formula above, it's clear that I need to calculate the voltage across the capacitor. But I only know how to calculate the voltage across something with a known resistance, using Ohm's Law. I guess my first question would be, how can I calculate the voltage across a capacitor? And once I have that, I can just use $$Q_C = C \Delta V$$ to calculate the charge.

edit: nevermind, I figured this out on my own.

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Last edited: Jan 28, 2009