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Homework Help: RL circuit current direction

  1. Oct 25, 2011 #1
    1. The problem statement, all variables and given/known data

    A circuit made with a battery, a switch, an inductor. and three resistors is shown in the figure. To begin with, switch S has been open for a long time. Then at time t = 0 the switch is closed.


    After being closed for a long time, the switch S is now opened.
    What is the direction of the current in the right hand loop containing L, R2 and R3 immediately after the switch is opened?

    (a) clockwise
    (b) counterclockwise Correct Answer

    2. Relevant equations

    Ampere's law?

    3. The attempt at a solution

    I am not sure how do I ind the direction of current if switch is opened? Should be no current?

  2. jcsd
  3. Oct 25, 2011 #2


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    Staff: Mentor

    Before the switch is opened, what currents are flowing and in what directions?
  4. Oct 26, 2011 #3
    There are current on r2,r3 and inductor and it is clockwise...
  5. Oct 26, 2011 #4


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    Staff: Mentor

    No, that's not right. Yes, there is current through the inductor, but what is that current and what is the voltage across the inductor? What about R1?
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