Monday, March 21, 2011

EE 2315 Circuits Homework 01 Node Voltage Analysis

Page 1: NodVol 01
             NodVol 03
             NodVol 07
Page 2: NodVol 09
             NodVol 11
             NodVol15
Page 1: NodVol 21

5 comments:

  1. are you sure your work is correct?

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  2. Well, you should definitely keep in mind that this work was done while I was taking Circuits I, so some problems may or may not be solved in a completely sound manner... however, most are, as all the answers that are up here came back as being correct (outside of a few that I may have transcribed incorrectly, as all my original work is done on a dry-erase board). Outside of that, I would stand by my work. Did you have a question regarding any problem in general?

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  3. Number 21 is confusing! How do you get V2?

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  4. I used some basic algebra (that sounds snarky, but I don't mean to be - I just want you to know where I am going with this).

    First, I used Ohm's law to describe the relationship between ix & V1. That gave me

    (1) ix = V1/15

    Next, I used KCL (Kirchoff's Current Law, wich states that the sum of the current in a node is zero) to give me an equation with V1 & V2 in it. That is where I came up with:

    (2) 0 = -45 + V1/15 + V2/25 + (V2-460)/40

    I then solved equation 2 to solve for V2 in terms of V1. I made a transcription error, which you will see fixed here:

    (3) V2 = (7*V1)/3 + V1
    (4) V2 = (10*V1)/3

    Now that I know what V2 is in terms of V1, I can go back to equation 2, and replace all of my V2 values with (10/3)*V1.

    (5) 0 = -45 + V1/15 + (10/3)*V1/25 + ((10*V1/3)-460)/40

    Next, solve equation 5 for V1 (I am assuming that my previous calculations were correct. You should do the calculations yourself to be sure).

    (6) V1 = 199.4 V

    Plug equation 6 into all the instances of V1 in equation 2:

    (7) 0 = -45 + 199.4/15 + V2/25 + (V2-460)/40

    Solve for V2:

    (8) V2 = 664.7 V

    Good luck!!!

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  5. Thank you so much! I didn't think you would reply. We had not seen this in lecture yet. We went over it today and it all made sense. Your solutions helped me a lot to finish my HW before we even got there in lecture.

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