# Noise across RC circuit

1. Oct 14, 2009

### Apteronotus

Consider two regions A and B connected by a parallel RC circuit.
Suppose the potential at region A has some noise component $$\xi(t)$$.
Then the current that will flow through the circuit due to it will be
$$I_{R}(t)+I_{C}(t)$$, ​
where each current is a function of the noise.

My question is; how do we calculate $$I_{C}(t)$$?

When I attempt this problem using $$I_{C}=\frac{dQ}{dt}$$, I get a term of the form $$\frac{d\xi}{dt}$$, which I'm told cannot be calculated.

Any suggestions would be very very appreciated.

Last edited: Oct 14, 2009