(i) An n-channel JFET has a pinch-off voltage of -4.5

(i) An n-channel JFET has a pinch-off voltage of -4.5 V and Idss = 9mA. 

(i) At what value of Vos in the pinch-off region will Ip equal 3 mA? 

(ii) What is the value of VDS (sat) when Ip=3 mA? 

(ii) What is the JFET transfer characteristic, and how is it important in JFET calculation

(iii) With the aid of diagram(s), explain how JFET can be used as a switch.