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Homework Help: Complex circuits

  1. Apr 13, 2008 #1
    1. The problem statement, all variables and given/known data



    determine the voltage across and the current through each resistor for the circuit.

    3. The attempt at a solution

    1&2=parallel 1/50+1/25=3/50 --> 50/3=16.7 ohms

    3&4=parallel 1/10+1/10=1/5 --> 5 ohms

    5&6=series 5+10=15 ohms

    total resistance=36.7 ohms

    so my question is how do you figure out the current and voltage with just the resistance given to you?
  2. jcsd
  3. Apr 13, 2008 #2
    Did they give you a battery voltage or emf?
  4. Apr 13, 2008 #3
    nope. thats why i cant figure out anything besides the resistance. i dont even think the question has possible answer.
  5. Apr 13, 2008 #4
    If you're not given a number for E, the answer has to be expressed in terms of E.
    Then use voltage division immediately (no loop or node equations necessary)
    R = total equivalent resistance
    V across (R1 parallel R2) = E ( [R1 parallel R2] / R)
    V across (R3 parallel R4) = E ( [R3 parallel R4] / R)
    Voltage across R5 = E (R5 / R)
    Voltage across R6 = E (R6 / R)
  6. Apr 13, 2008 #5
    what does the E stand for? current?
  7. Apr 13, 2008 #6
    I meant voltage source E. I got you mixed up with someone else who had a battery named E.
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