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Homework Help: Capicitance and Voltage (HELP!)

  1. Feb 11, 2010 #1
    I am really confused on how to solve this Physics question. I attempted the first one but is wrong for some reason.

    A 7.0 micro F and a 3.0 micro F capacitor are connected in series and this combination is connected in parallel with a 4.4 micro F capacitor.

    a) What is the net capacitance?
    b) If 24 V is applied across the whole network, calculate the voltage across each capacitor.

    For part a, i tried to do:

    1/Net Capacitance = 1/(7+3) + 1/4.4 and got 3.056 for the net capacitance. However, it is saying that i am wrong. Can you tell me what i am doing wrong?
     
  2. jcsd
  3. Feb 11, 2010 #2

    kuruman

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    First find the capacitance of the series combination. What is it?
     
  4. Feb 11, 2010 #3
    haha nvm i get part a

    for part a i got 1/7 + 1/3 and took the inverse of that then added it to 4.4 XD

    how do you do part b?
     
  5. Feb 11, 2010 #4

    kuruman

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    You have a 1/7 + 1/3 μF capacitor in parallel with a 4.4 μF capacitor. What is the voltage across the 4.4 μF capacitor? What is the voltage across the 1/7 + 1/3 μF combination capacitor?
     
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