1. Not finding help here? Sign up for a free 30min 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!

Find the current

  1. Jul 3, 2017 #1
    1. The problem statement, all variables and given/known data
    the image of circuit is in attachment
    the question is to find the current through the battery

    2. Relevant equations


    3. The attempt at a solution
    I think that there is a y connection
    so above two and centered one form y from formula the whole resistance is 1
    than I imagine bottomed ones and this and above ones as new y type connection and
    I get 1/R = 1/(1/1 + 1/2 + 1/3) and r is equal to 11
    all in all the current should be I=U/R = 3/11
    but in book the answer is 21/19
    please help
     

    Attached Files:

  2. jcsd
  3. Jul 3, 2017 #2
    you can use delta to y conversion
     
  4. Jul 3, 2017 #3

    gneill

    User Avatar

    Staff: Mentor

    Please show the formula used and the details of how you applied it for your Y to Δ transformation. What do you mean by the "whole resistance is 1"?
     
  5. Jul 3, 2017 #4
    upload_2017-7-3_19-59-46.png
    this is the your current equivalent circuit you could change it to the form of
    upload_2017-7-3_20-1-41.png
    using
    sorry for my poor drawing skills
     
  6. Jul 3, 2017 #5
    1/R = 1/(1/r1+1/r2+ 1/r3)
     
  7. Jul 3, 2017 #6
  8. Jul 3, 2017 #7
    i am sorry i will draw again
    upload_2017-7-3_21-19-52.png
    the 3 and 2 are the same old resistors but Ra , Rb , Rc are resistances to be determined using the delta to y conversion hope this clears up
    what i am saying is that this circuit is equivalent to the old circuit if proper values of resistance for a b and c are used
     
  9. Jul 3, 2017 #8
    i dont understand what formula that is
     
  10. Jul 3, 2017 #9

    lewando

    User Avatar
    Gold Member

    This is the formula for finding the equivalent resistance of 3 resistors in parallel. Not the delta-wye formula.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Find the current
  1. Find current (Replies: 7)

  2. Find the current (Replies: 3)

  3. Finding Currents (Replies: 4)

  4. Find the current? (Replies: 40)

  5. Finding the current (Replies: 4)

Loading...