9.a) Define all the four hybrid parameters of a BJT in CE configuration. Draw the circuit and its equivalent circuit. b) The source and load resistances connected to a BJT amplifier in CE configuration are 6800 and 1 KQ respectively. Calculate the voltage gain AV and the input resistance R; if the h-parameters are listed as he = 1.1 k; hr = 2104; he 50 and hoc= 20 mhas. Compute Ay and R; using both approximate and exact analysis. 10.a) With the help of a neat schematic, explain the functioning of a common source amplifier. b) Bring out the differences between BJT and FET. Compare the three configurations of JFET amplifiers. OR 11.a) Differentiate between enhancement and depletion modes of a MOSFET with the help of its characteristics and construction. b) Determine the pinch off voltage for an N - channel silicon. JFET if the thickness of its gate region is given as 3.2104cm and the donor density in n-type region is 1.2x105/cm. c) Establish a relation between the three JFET parameters, , Ia and gm.