JFET transistor help?

Question

in the circuit at the link below, how would i find: IDQ, VDS, and VGS. For this JFET.

I'm new to electronics and need some directions. Thanks
http://img.photobucket.com/albums/v233/jster28/untitled.jpg

Answer 1

Treat the transistor as having a very high input impedance. Calculate the voltage across the R1, R2 voltage divider. Now transfer that voltage to R3 by subtracting the threshold voltage of the FET from the voltage at the divider. Calculate the current through R3 based on that voltage. That'll give you Idq. And you should be able to get the rest from there. Vgs is just the threshold.