Question five a) Explain briefly the (i) cutoff, (ii) triode and (iii) saturation regions of the operation of a MOSFET device. (6 marks) b) For the circuit shown in Fig. 8 below find the value R that results in achieving VD=0.8V. Note that the MOSFET has the following characteristics, threshold voltage Vt=0.5V, unCox=0.4mA/V², W/L-0.72/0.18 and also neglect effects related to channel length modulation. Note that when operating in the saturation region the following equation holds: 1 W ID=μn Cox (VD-V+)² L +1.8V R -O VD (10 marks) Fig. 8 c) What is a P-N junction? Explain the formation of potential barrier and depletion layer. Assume in your answer that there is no external voltage applied in the junction. (9 marks)