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

Greetings to all,

I cant work the Vth out (across terminals a and b) from the circuit in the image I've attached here.

There was a hint in the question too:' ... Define the voltage at the left most node as 'v', and write 2 nodal equations with Vth as the right node voltage'. The answer for Vth given in the book is 30V.

2. Relevant equations

3. The attempt at a solution

I've tried according to the hint given but my answer didn't match. Maybe there is a mistake with my nodal equations...? This is what I came up with:

For node a: 'v'= ir= 60*4= 240V

For node b: Vth/80 + Vth/40......= 0 --------> (1)

and Vth/40 = i delta ----->(2)

Yeah I know that in the 1st equation I didnt include a term for the 20Ω resistor as I'm not sure about how to because of the dependent voltage source in between (and when I somehow did, I got weird answers :S). So, I'd appreciate it very much if anyone would kindly show me the correct set of nodal equations I need to construct to get the correct answer for Vth.

Thank you c:

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# Homework Help: A circuit problem from Thevenin's theorem (I cant work Vth out!)

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