Relating currents and resistance

Thread Starter


Joined Jan 30, 2007
I have attached a picture of the problem.
Part 1: Use Kirchhoff's current law to determine the unknown currents in the circuit shown. Assume that I0=-2A, I1=-4A, Is=8A and Vs=12V.
Part 2: Use Ohm's law to find the resistances R1, R2, R3, R4 and R5 if R0= 2 ohms. Assume R4=(2/3)R1 and R2=(1/3)R1.

My work:
For the first part I set up the equations:
I0+I1+Is-I3=0 I found I3=2A.
I0+I1+I2=0 I found I2=6A.

For the second part I attempted to use R=V/I. I know that Vs=12. But when I applied this I got:
R1=(12/-4)=-3 ohms
R2=(12/6)=2 ohms
2 is not (1/3)3 [R2=(1/3)R1]

I was wondering where I messed up in the 1st part and/or 2nd part.