(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

http://img509.imageshack.us/img509/5658/circuituz5.jpg [Broken]

Find the current through resistor X for V = 7V

2. Relevant equations

Thevenin equivalence?

3. The attempt at a solution

Right I was advised a way to do this by assuming a 1A current flows through the resistor and then working back and scaling accordingly, but I also want to try this using Thevenin Equivalence. So I've worked out:

Vth = 0.46V and Rth = 4.28 ohms

Working for Rth:

Rth is the resistance seen accross X with V shortcircuited. Thus, starting from right with 1 ohms (i.e. X) going to left

= [(((((((1||2) || 3) -- 2) || 7) -- 2 -- 1) || 4 -- 2) || 5) -- 2] , where || denotes parallel, -- denotes series. I think this is where I've messed up, giving me 4.28 ohms

Working for Vth:

Jus use voltage division from 7V all the way down to give 0.46V accross X

So the Thevenin equivalent is:

0.46V in series with 4.28 ohms and then the load (resistor X) connected is 1 ohm in series.

This doesn't give the correct answer though. The current is supposed to be 0.125A.

Any feedback/help/advice very much appreciated!

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# Homework Help: Circuit analysis (thevenin equivalence)

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