How the heck do you solve this Thevenin Equ. Problem?

Discussion in 'Homework Help' started by thatsmessedup, Apr 26, 2018.

  1. thatsmessedup

    Thread Starter New Member

    Feb 15, 2018
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    So I've never seen a question like (b) so I do not know how to tackle it. Can I get a helpful hint? Thanks.

    The question:
    b.PNG

    The provided answer:
    ansb.PNG

    My work leading up to question (b):
    20180426_185209.jpg
     
  2. WBahn

    Moderator

    Mar 31, 2012
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    6,828
    What do you get if you express V1 in terms of is2?
     
  3. thatsmessedup

    Thread Starter New Member

    Feb 15, 2018
    22
    0
    I know for a resistor you can do v^2/R but I do not know how to express v1 in terms of is2.
     
  4. danadak

    Well-Known Member

    Mar 10, 2018
    1,450
    296
    You have a Vsource - Is2 x R = V1

    Regards, Dana.
     
  5. The Electrician

    AAC Fanatic!

    Oct 9, 2007
    2,561
    459
    So far you have solved the circuit twice. Once with is2 replaced with a short to calculate isc, and again with Vs replaced with a short to calculate Rth. You could now solve for the voltage across is2 in the original circuit using the network solving techniques you know. Or, you could do it using the Thevenin equivalent you obtained. Look at the last circuit in your working. You have a -7.31 volt source in series with a -161 Ω resistor and then in series with a current source of is2 amps. The current source will force a current of is2 amps through the -161 Ω resistor, so what will be the voltage across that resistor? That will make the value of V1 equal to the sum of -7.31 volts and the drop across the -161 Ω resistor. That gives you an expression for V1 in terms of is2.
     
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  6. thatsmessedup

    Thread Starter New Member

    Feb 15, 2018
    22
    0
    Thanks The Electrician for the help in solving this circuit and to the rest of you for your helping hand!

    20180428_091725 (1).jpg
     
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