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AC Source driving an RLC circuit...

  1. Aug 23, 2018 #1
    1. The problem statement, all variables and given/known data

    10 v, 100 hz goes into a circuit of a 1o resistor, a 1o inductive reactance and a 1o capacitive reactance that are in series.

    What is the current. What is the V across the cap.



    2. Relevant equations and the attempt at a solution

    So I know I = V/Z and Z = sqrt( R^2 + (XL^2 - XC^2 )

    And the question gives us the inductive reactance and capacitive reactance which is XL = 1 and XC = 1, and it gives us R = 1

    So now, Z = sqrt(1^2 + (1^2 - 1^2 ) ) = 1

    And I = V/Z = 10/1 = 10 A

    Is that correct for the current of the circuit? If so, how do I calculate the voltage across the capacitor?

    Is it voltage of capacitor, Vc = I * XC = 10 * 1 = 10 V ? Is that correct?
     
    Last edited: Aug 23, 2018
  2. jcsd
  3. Aug 23, 2018 #2
    Yes, that is the correct value of the current.

    and the voltage across the capacitor is almost correct.

    Revisit your XL and XC. Isn't there a "j" in the reactance?
     
  4. Aug 23, 2018 #3
    Ah, would it be, Vc = I * Zc = 10 * (1/j) = 10/j = -10j
     
  5. Aug 23, 2018 #4
    Now it is correct. Nice work!
     
  6. Aug 23, 2018 #5
    Thanks
     
    Last edited: Aug 24, 2018
  7. Aug 24, 2018 #6
    Yes, you've got it right.
     
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