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Homework Help: Maximum power transfer

  1. Oct 16, 2015 #1
    1. The problem statement, all variables and given/known data
    The question is showed as below.

    2. Relevant equations
    I don't know how to find i when the resistor is 4 ohm.
    I think it is quite difficult as the voltage is varying all the time.
    So how do I find the current?

    3. The attempt at a solution

    Attached Files:

  2. jcsd
  3. Oct 16, 2015 #2


    User Avatar

    Staff: Mentor

    Relevant equations are those equations you feel are relevant to the type of problem, not a continuation of the problem statement.

    What sort of circuit might you replace the internals of the black box with in order to give you something to work with? You have several external data points you can use to determine the parameters of that circuit model (think: simultaneous equations, solve for required parameters).
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