Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Series-parallel circuit

  1. Aug 22, 2010 #1
    1. The problem statement, all variables and given/known data

    Can anybody help me solve this circuit?I wanna find V1, V2, V3, I1, I2, I3.Power supply is 40V.

    2. Relevant equations

    3. The attempt at a solution

    Attached Files:

  2. jcsd
  3. Aug 22, 2010 #2
    it's not very difficult to work with.
    Please show part of your soln or some views.

    you may first find V2.
  4. Aug 22, 2010 #3
    Well,I don't know what to do at all.I hv found the total resistance,15.975 Ω ,and total current,2.504A.Is it correct?What to do next?Step by step if possible...
  5. Aug 22, 2010 #4


    User Avatar
    Gold Member

    Those are close to the values I got: 16.265 ohms and 2.459 amps.

    I would next find the voltage across the 11 ohm resistor.
    From there you can determine the voltage drops across the 3 legs of your circuit, which will lead you immediately to I1.
    And although they don't ask for it, you should then find the current through the 12 ohm resistor.
    Knowing the currents through the 11, 12, & 13 ohm resistors will yield the current through the 14 ohm resistor. That will give you V3.
  6. Aug 22, 2010 #5
    I don't think the equivalent resistance is 15.975 but 16.265

    Sorry, I made a typing error.
    You may first find "V3", by calculating equivalent resistance of the very right part.
    then you may find V3 by the ratio of resistance
  7. Aug 22, 2010 #6
    Can you tell me what are the final answers?Pls include the steps/calculation to get the answers.
  8. Aug 22, 2010 #7


    User Avatar
    Science Advisor
    Homework Helper

    Welcome kai92 to the PF forums!!
    The people here are trying to help you. However you may want to review part 1 of https://www.physicsforums.com/showthread.php?t=94379" to appreciate what is expected of those requesting assistance.
    You could start by telling us what you know about Kirchhoff's Laws applied to circuits.
    Last edited by a moderator: Apr 25, 2017
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook