1. Feb 15, 2010

### vortex193

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

V = 1.2 kV
R1 = R2 = R3 = 0.75 MegaOhms

With C uncharged, switch S is closed (t = 0). At t = 0, what is the current through each resistor? At t = infinity, what is the current through each resistor?

2. Relevant equations

V= IR
q = qo[1 - e^-t(RC)] (charging of capacitor
q = qoe^-t/(RC)] (discharging of capacitor)

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

Last edited: Feb 15, 2010
2. Feb 15, 2010

### xcvxcvvc

umm... how exactly are those components arranged and what is the problem asking you to find?

3. Feb 15, 2010

### vortex193

sorry guys. the question is:
With C uncharged, switch S is closed (t = 0). At t = 0, what is the current through each resistor? At t = infinity, what is the current through each resistor?

4. Feb 15, 2010

### vortex193

do you see the picture? if not here is the link:
http://tinypic.com/r/20fyjkn/6

5. Feb 15, 2010

### xcvxcvvc

At t = 0, an uncharged capacitor has zero charge on it and zero voltage drop across it. At t = infinity, a capacitor's plates are fully charged and have no current going "through" them.

6. Feb 15, 2010

### vortex193

but its not asking for the current through the capacitor but the current through the resistor

7. Feb 15, 2010

### willem2

At t=0 the circuit is equivalent to a circuit with C replaced by a wire.
At t=infinity the circuit is equivalent to a circuit with C replaced by an open switch.

You should be able to figure out the currents in these resistor only circuits.

8. Feb 15, 2010

### xcvxcvvc

Yes, but if it has zero current through it, it looks like an open circuit, and if it has a drop of zero volts, it looks like an short circuit. I was trying to get you to arrive to the answer instead of stating it.