RAJIV GANDHI COLLEGE OF ENGINEERING AND TECHNOLOGY DEPARTMENT OF ECE QUESTION BANK- EDC SEMESTER - III UNIT I : SEMICONDUCTOR DIODS PART A

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1 RAJIV GANDHI COLLEGE OF ENGINEERING AND TECHNOLOGY DEPARTMENT OF ECE QUESTION BANK- EDC SEMESTER - III UNIT I : SEMICONDUCTOR DIODS 1. Define Electronics. 2. What is meant by forbidden energy gap. 3. Classify the materials based on conductivity. 4. What is semiconductor? Mention the types of semiconductor. 5. What are active and passive components? 6. What is intrinsic semiconductor? Give example. 7. What is extrinsic semiconductor? Give example. 8. What is drift current? 9. What is diffusion current? 10. What are donor and acceptor impurities? 11. What is forward and reverse bias? 12. Define reverse saturation current. 13. Define breakdown voltage. 14. What is maximum forward current? 15. Define Peak Inverse Voltage. 16. What is maximum power rating? 17. Write the diode current equation and mention the parameters in it. 18. What is static and dynamic resistance? 19. Define transition capacitance and diffusion capacitance. 20. What is meant by doping in a semiconductor? 21. What is meant by N type and P type impurity? 22. What is PN junction diode? How is it formed? 23. Explain how a barrier potential is developed at the PN junction. 24. Define avalanche breakdown. 25. What is zener breakdown. 26. Mention the applications of PN junction diode. 27. Mention the applications of zener diode.

2 1. Describe the action of PN junction diode under (a) no bias (b) forward bias (c) reverse bias. Also draw its VI characteristics. 2. Explain the operation of zener diode and give its VI characteristics. 3. Discuss on (i) The temperature effect on PN junction diode, (ii) Transition and diffusion capacitors. 4. Derive the current equation for a PN junction diode. UNIT II : TRANSISTORS 1. What is a bipolar junction transistor? Why it is named so? 2. What are the various types of configurations of BJT? And mention the three regions of working. 3. What is base-width modulation? 4. What is punch through? 5. Define input impedance. 6. Define output admittance. 7. Define forward current gain. 8. Define reverse voltage gain. 9. What is current amplification factor? 10. Compare CB, CE & CC configurations. 11. Mention the advantages of JFET over BJT. 12. Compare JFET and BJT. 13. What is pinch of voltage? 14. Why JFET is called as a voltage controlled device? 15. What are the various regions of operation for a JFET. 16. What are the applications of JFET? 17. Compare N channel with P-channel FETs. 18. What is trance conductance? 19. What is drain resistance? 20. Define amplification factor. 1. Explain the operation of NPN and PNP transistors and its various current components using necessary diagrams. 2. Explain CB configuration of a transistor and give its input and output characteristics. 3. Explain CE configuration of a transistor and give its input and output characteristics. 4. Using the basic structure of JFET. Explain its physical operation and draw its output characteristics. Give expression for drain current. 5. With a neat diagram explain the working of i) Enhancement mode MOSFET and ii) Depletion mode MOSFET. UNIT III : SPECIAL SEMICONDUCTOR DEVICES

3 1. What is meant by tunnel diode? 2. Draw the VI characteristics of tunnel diode. 3. List out the applications of tunnel diode. 4. What is PIN diode? And mention its applications. 5. What is veractor diode? And mention its applications. 6. What is meant by SCR? List out the advantages of SCR. 7. What is UJT? And mention its application. 8. List out the applications of DIAC and TRIAC. 9. What is photo diode? And list out the classifications of photo diode. 10. What are the futures of photo diode? 11. What is meant by solor cell? 12. What are the applications of solor cell? 13. What is LED? What are the basic principles of LED? 14. List out the applications of laser diode. 15. What is LCD? 16. What is LDR? 17. What is firing angle and conduction angle of SER? 18. What is schottky barrier diode? 19. What is laser? 20. What is MESFET? 1. Describe the working principle of SCR with VI characteristics. 2. Describe the operation of TRIAC and sketch its characteristics. 3. Describe the operation of DIAC and sketch its characteristics. 4. Describe the operation of UJT and sketch its characteristics. 5. Explain the construction and working of PIN diode under forward and reverse condition. 6. Discuss the operation of varactor diode and list out its application. 7. Discuss the functions of LED and LCD. 8. Explain the principle behind the laser diode and discuss the various types of laser diode. UNIT IV : BIASING AND STABLIZATION 1. What do you understand by Operating point? 2. Why do we choose the Q point at the center of the load line? 3. Name the two techniques used in the stability of the Q point. Explain. 4. Define stability factor and give the expression for stability factor. 5. List out the different types of biasing. 6. What do you meant by thermal runway? 7. Why transistor is called as a current controlled device? 8. Define current amplification factor. 9. What are the requirements for biasing circuits?

4 10. When does a transistor act as a switch? 11. What is biasing? 12. What is an operating point? 13. What is D.C load line? 14. Explain about the various regions in a transistor. 15. Explain about the characteristics of a transistor. 16. Why the operating point is selected at the centre of the active region? 17. What is an amplifier? 18. What is small signal amplifier? 19. Why bias compensation is required? 20. What is voltage divider biasing? 21. What are the advantages of self biasing? 22. What is the need for heat sink? 23. What is meant by thermal runaway? 24. What is bias stabilization? 25. What are the temperature sensitive resistive devices? 26. What is FET and FET biasing? 27. What is the difference between BJT and FET? 28. Why thermal run away does not occur in FET? 29. Why CE amplifier is most commonly used compared to other configurations? 30. Define VVR or VDR. 1. Explain self biasing of a BJT with neat diagram and derive its stability factor. 2. Discuss about thermal runaway and state the condition for avoiding it. 3. Explain in detail about three types of biasing for BJT with neat diagram. 4. Draw the fixed bias and self bias circuit using FET. Explain in detail. 5. Explain thermal runaway and heat sink in detail. 6. What is meant by compensation and explain the diode compensation for instability due to V BE variation. 7. Explain voltage divider biasing in FET. 8. Explain in detail about how thermistors are used for bias compensation against temperature effect. UNIT V : POWER SUPPLIES 1. What is a voltage multiplier? 2. What is meant by ripple factor? 3. Define line regulation. 4. Define load regulation. 5. What are the limitations of using zener diode regulator? 6. What is the basic concept of SMPS? 7. Indicate two advantages of bleeder resistor. 8. What are the advantages of bridge rectifier? 9. Why is a simple capacitor filter not suitable for heavy load?

5 10. Define switching regulator. 11. Differentiate series and shunt voltage regulator. 12. Define Rectifier. 13. What are the different types of rectifiers? 14. What are the different types of transformer? 15. Define transformer utilization factor. 16. Define filter. 17. Define voltage regulator. 18. Classification of voltage regulator. 19. Classification of voltage doubler. 20. Compare the efficiencies of half wave rectifier and full wave rectifier. 1. Explain in detail about different types of filters. 2. Explain in detail about bridge rectifier circuit. 3. Describe in block diagram the series and shunt voltage regulator and explain the operation of transistorized series regulator. 4. Explain in detail about different types of voltage multiplier. 5. Explain step up and step down converters. 6. Explain in detail about half wave and full wave rectifiers with suitable wave forms.