Best solution for me is using Kirchhoff´s law: 1) Sum of currents in one joint equals 0 2) Sum of voltages in one loop (don´t know the right term) is equal to zero. Look at www.allaboutcircuits.com for explanation
Once you have reviewed the material contained in the link that Dave has posted, then give the calculation a whirl and then post your calculations and your results. We will be happy to provide you a bit of guidance if needed. hgmjr
I came up with 13K for R2. Vo = 0.25ma * 5K +0.7V Vo = 1.95V I1= I2 + ID I1 = 12V/30K =0.4mA ID = 0.25mA (Given) I2 = 0.4-0.25 =0.15mA V0 = 1.95V R2 = 1.95V/0.15mA = 13K
The part about 12v/30k doesn't look right; the voltage drop across the 30k can't be all of the 12v, it's got to be something less than that, seems like about 9 or 10 volts, because you've got to subtract the voltage drops caused by all of the 3 remaining components. I got 40678, but I don't have time to check it before I leave---Sorry, Rich