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Bob Loblaw
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Homework Statement
http://img207.imageshack.us/img207/1685/p1854altco4.gif
Find the unknown emf and the unknown currents in the circuit below, in which R = 3.48 . Take the positive direction for current flow in each branch to be upwards.
EMF = V
left branch= A
right branch= A
Homework Equations
Kirchhoff's circuit laws
The Attempt at a Solution
I added current lines to the diagram. Note that a coordinate system is imposed and all positive charges point up ( I guess this makes grading easier). I sketched the lines of current as best I could.
Here are my equations:
Left loop:
1.00v-3.48I1-E+(.05*2)
Outside loop:
1.00v-3.48I1-1.00I3+1.20V+4.00I3=0 (edit: caught a mistake here, last term should have been positive)
Apply junction rule to top center junction:
I1+.05=I3
Combine terms:
1.00v-3.48I1-E+.1=0
2.20v-3.48I1+3.00I3=0
Substituting I1+.05 for I3:
2.20v-3.48I1+3.00I1+.15=0
Combining like terms:
2.35-.48I1=0
I1(the left loop)=4.90A which is wrong.
Any ideas where I messed up?
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