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Calculation On Transformer

  1. Mar 19, 2012 #1
    1. The problem statement, all variables and given/known data

    Hello everybody, am confronted with this question:
    A transformer with 5500 turns in its primary is used between a 240V a.c supply and a 120V kettle. Calculate the number of turns in the secondary.

    2. Relevant equations

    The equation Es/Ep = Ns/Np can be applied in solving the problem.
    Where Es = e.m.f of secondry. Ep = e.m.f of primary, Ns = number of turns in secondary coil, Np number of turns in primary coil

    3. The attempt at a solution

    Using the formular:
    Es/Ep = Ns/Np
    Where Np = 5500turns
    Ns = ? becuase am required to calculate for it.
    For Es and Ep, I don't know the value to substitute in for Es and Ep respectively. Whether is the 240V or 120V. I don't know between 240V and 120V the one that is Ep or Es respectively.
    I can't go further with the calculation since am unable to substitute in the values into the equation correctly. Can sombody help me here please?
     
  2. jcsd
  3. Mar 19, 2012 #2

    tiny-tim

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    hi chikis! :smile:
    the coil with the electricity source going through it is always the primary :wink:
     
  4. Mar 27, 2012 #3
    Thank you very much tiny-tim,
    that answer have solved my problem. I will work the problem and forward the working in for all to view. Thank you once again, am very greatful.
     
  5. Mar 27, 2012 #4
    Thank you very much tiny-tim,
    that answer have solved my problem. I will work the problem and forward the working in for all to view. Thank you once again, am very greatful.
     
  6. Mar 31, 2012 #5
    Here is the working:
    Ep/Es=Np/Ns
    =240/120=5500/Ns
    :.
    Ns=5500*120/240
    =2750
    My thanks goes to tim-tim who has contributed immensly to this thread.
     
  7. Mar 31, 2012 #6

    tiny-tim

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    yes that's fine! :smile:
     
  8. Mar 31, 2012 #7
    Thanks for that compliment.
     
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