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Homework Help: Laplace transform

  1. Oct 7, 2014 #1
    1. The problem statement, all variables and given/known data
    we have to solve the given circuit using laplace transform for i(t) for t>0 when switch k opened at t=0..
    now all I wnated to make clear is the final circuit diagram of this in s-domain..

    2. Relevant equations

    3. The attempt at a solution
    as I solved I considered the circuit to be in steady state before switch is opened so , current across inductor is 6A...

    Attached Files:

  2. jcsd
  3. Oct 7, 2014 #2
    Images are not clear.
  4. Oct 7, 2014 #3
    What is i(0+) you are getting ?
  5. Oct 7, 2014 #4
    well only the left hand portion is'nt clear.. in 1st pic.. there is 12V voltage source & in 2nd pic it is 12/s in s-domain..
    i(0+)=i(0-) = 6A..
  6. Oct 7, 2014 #5
    can you show your working for i(0-).
  7. Oct 7, 2014 #6
    sorry actually I did a calculation mistake..i(0-) =4 A.. and I found the equivalent current of the circuit considering it in steady state before switch is opened.. so the inductor is dhorted so the whole 4 A current pass across the inductor branch..!!
  8. Oct 7, 2014 #7
    Are you sure the current will be 4 A,mine is coming 14 A.
  9. Oct 7, 2014 #8
    you are right ..:rolleyes: ..
  10. Oct 7, 2014 #9
    Your second image is correct.
  11. Oct 7, 2014 #10
    thanks and additional thanks for correcting that mistake.. :p
  12. Oct 7, 2014 #11
    You are welcome.
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