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B Xc and XL relation after a change of frequency

  1. May 17, 2018 #1
    I am getting ready for exams and I have encountered this problem on the exam paper: In AC circuit there is a condensator and a inductive coil, At first XL=XC, how does the relation change when the frequency doubles? The answer says XL=4XC Can someone explain me how they come to this conclusion? Thanks in advance
  2. jcsd
  3. May 17, 2018 #2


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    What is the formula for Reactance of a C and an L? Write those formulae down and substitute f with 2f; what do you get? It's pretty simple maths.
  4. May 20, 2018 #3
    It is a purely conceptual exercise. You do not need to write formulas. Respond conceptually. Is ##X_L## inverse or directly proportional to the frequency? And the same question for ##X_C##. This takes you directly to the result.
  5. May 20, 2018 #4
    Yeah, thank you for response, already got the answer.
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