# JFET question

1. Nov 23, 2006

### Hybird

I have a problem of calculating the current through a system. It is a simple JFET transistor with the source grounded. The gate is reverse biased with a 3v potential, and the drain has a 2000 ohm resistor in series then a positive 20v potential in series which is of course grounded. How would I go about finding the current through the load resistor?

2. Nov 23, 2006

### Hybird

...Assuming an n-type Si transistor

Also I dont have any other information.. I know that the more and more you apply a negative voltage on the gate, the smaller the channel gets which leads to more resistance across the source-drain channel. The answer Im lookin for is 2mA.. that would lead to a resistance of 8000 ohms, cause we still have a 2000 ohm resistor in series therefore 10000 ohm and with a voltage across the source-drain channel of 20 volts.. you get your 2mA answer, I dont see how you can get this bridge voltage without knowing something about a family of curves or the like???

Last edited: Nov 23, 2006