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Homework Statement
http://imageshack.us/a/img822/5921/homeworkprobsg22.jpg
Determine the values of the node voltages Va and Vb
Homework Equations
Nodal analysis, V = IR
maybe KVL and/or KCL
The Attempt at a Solution
I got the wrong answer / not sure what the reference node is used for (I know it's the one connecting to ground though, does it have to do with the current?)Vb - Va = 12V
Vb = Va + 12VKCL at a:
1.5A + I = Va/6Ω
I = -1.5A + Va/6ΩKCL at B: 3.5A + I + Vb/3Ω = 0Plugging Vb into KCL at b:
3.5A + I + (Va + 12)/3Ω = 0Now plugging in KCL at a, and then solving for Va:
3.5A -1.5A + Va/6Ω + (Va + 12V)/3Ω = 0
2A + (Va + 2Va + 24V)/6Ω = 0
2A + (3Va + 24V)/6Ω = 0
(3Va + 24V)/6Ω = -2A
3Va + 24V = -12V
3Va = -30V
thus
Va = -10V which is supposedly wrong and would make Vb = 2V also wrongWhere did I go wrong?Thank you.
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