1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

RC circuits help

  1. Oct 2, 2011 #1
    1. The problem statement, all variables and given/known data
    I attached the problem

    I don't understand why the 3 resistors at the top end up being in series for part b. can someone explain that to me.

    2. Relevant equations

    3. The attempt at a solution

    Attached Files:

  2. jcsd
  3. Oct 2, 2011 #2


    User Avatar

    Staff: Mentor

    After a long time, when the circuit reaches steady state, the capacitors will be charged to their steady state values and no further current will flow into or out of them. Essentially, as far as the current is concerned, they no longer exist in the circuit.

    If you take your eraser and remove the capacitors, what doe the circuit look like?
  4. Oct 2, 2011 #3
    Ohh i see thanks a bunch. But even if i erase the capacitors and have just a wire in their place, wouldn't it still look like the 3 are in parallel?
  5. Oct 2, 2011 #4


    User Avatar

    Staff: Mentor

    By erase I mean eliminate completely. Leave no trace! Not even wires!
  6. Oct 2, 2011 #5
    Oh i see. part c of the question asks for the charges on the plates of the capacitors a long time after switch S is closed. If I play kirkoff's loop rule to the capacitor with the 10 microfarads, which resistors would I have to include in the equation?
  7. Oct 2, 2011 #6
    wait never mind I wasn't thinking. "loop" so I just take one of the triangles at the top and apply the loop rule.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: RC circuits help
  1. RC Circuit Help (Replies: 1)

  2. RC Circuit Help (Replies: 3)