3. (20%) For the circuit in Fig. 4, find the range of vl, over which Qlis operating in saturation. Under such condition, find the output voltage. Assume the threshold voltage

5. (20%) A common- -source amplifier using an NMOS transistor biased in the manner of Fig. 6 for which gm = 2 mA/V is found to have an overall voltage gain Gv of -16 V/V. What value should a resistance Rs inserted in the source lead have to reduce the voltage gain by a factor of 4?