Answer Happy

1. Explain the operation of a PNP Transistor under common base configuration using the Band diagram. Find expression of total Emitter Current, Transport Coefficient and Injection Efficiency. Show that current gain is less than one under this configuration? 2. Describe in details the principle of Gunn effect oscillator using the band structure of the material concerned. Find an expression of electron temperature for such material. What are the criterion to obtain oscillation in such material? Describe the principle of operation of Tunnel Diode and explain the I-V characteristics in reverse as well as in forward bias. Mention the conditions required to obtain current through such junction. 3. Derive Boltzmann Transport Equation introducing relaxation time. Derive the expression of electrical conductivity for a non-degenerate semiconductor. Show the variation of mobility with temperature for non degenerate semiconductor. 4. Show the configuration of a JFET with a neat diagram. Find an expression of drain current when drain voltage is small. Mention the application of this device in this mode. Find also the drain current when the drain voltage is large.