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!

3 batteries and 3 capacitors

  1. Oct 19, 2011 #1
    1. The problem statement, all variables and given/known data

    Three capacitors C1–C3, all initially uncharged, are placed in the circuit show above. The capacitances are C1=15.2 μF, C2=9.8 μF, C3=4.4 μF, and the battery voltages are V1=20 V, V2=20 V, V3=5 V.

    What is the magnitude q1 of the charge on capacitor C1 once equilibrium has been established?

    What is the magnitude q2 of the charge on capacitor C2 once equilibrium has been established?

    What is the magnitude q3 of the charge on capacitor C3 once equilibrium has been established?

    2. Relevant equations

    V=Q/C
    I1+I3=i2


    3. The attempt at a solution

    I tried applrying the kirchhoff's rule, but i dont know where to go with it... i dont even know if i am write or not.
    V1+Q1/C1 + Q2/C2+V2=0
    V3+Q2/C2+V2+Q3/C3=0
     

    Attached Files:

    Last edited: Oct 19, 2011
  2. jcsd
  3. Oct 19, 2011 #2

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    No figure is visible, so it's impossible to help you.
     
  4. Oct 19, 2011 #3
    really sorry about that. I didnt realise
     
  5. Oct 20, 2011 #4

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    For the loop with V1+Q1/C1 + Q2/C2+V2=0: Assuming the voltage drops are for traversing the loop in a Clockwise sense, there is a voltage drop across the capacitors. This equation should be:
    V1 - Q1/C1 - Q2/C2 + V2=0 .​

    Similarly, the signs for the voltages across the capacitors in the other loop equation should also be changed.

    Additionally, you have Q1 + Q3 = Q2, because I1 + I3 = I2 .

    Plugin all the values, do some algebra and see what you get.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: 3 batteries and 3 capacitors
  1. 3 plate capacitor (Replies: 9)

  2. 3 batteries? (Replies: 2)

Loading...