Please help!

Thread Starter

xnager23

Joined Sep 20, 2007
1
Hello,

For the attached circuit i have to find the current through each resistor using 3 methods: mesh, node voltage, and superposition.

For Mesh Method:
I1: clockwise in square ABFD
I2: counterclockwise in square CBFE
I3: clockwise in DFE

Formulas used:
Mesh 1: 10 = 7(I1)+2(I2)
Mesh 2: 20 = 2(I1)+9(I2)+4(I3)
Mesh 3: 0=-4(I2)-6(I3)

From this i get currents of I1=0.579A, I2=2.975A, I3=-1.983. I then use these to find values of current over each resistor.

Now when i try the node voltage method i am supposed to get the same current across each resistor but i do not.

The equations i have for the node voltage method are(# by I is resistor):
I1=(Va-Vb)/R1
I2=(Vf-VB)/R2
I3=(Vb-Vc)/R3
I4=(Ve-Vf)/R4
I5=(Vd-Ve)/R5
Vc=20-Ve
Vd = Vf = Ground = 0 V
I1+I3=I2 at Node B (using KCL)
I2+I5=I4 at Node F (using KCL)

When using these equations i do not get the same values of I for each resistor as in part 1.

For superposition method, i have no clue on how to reduce the circuit to one equivalent resistor for each of the power sources seperately.

Please, any information/help would be appreciated!!!
 

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