QUESTION BANK
UNIT I
PART A
1. Why a semiconductor is acts as an insulator at ordinary temperatures
2. Give the expression of depletion capacitance of a diode.
3. Draw the energy band structure of conductor
4. Differentiate drift current and diffusion current
5. Define n-type material and p-type material
6. What is PN junction? How is it formed?
7. What are the applications of a Diode?
8. What is mean by static and Dynamic resistances?
9. What is mean by Transition and diffusion capacitances?
10. What is mean by diode reverse recovery time?
PART B
1. Explain in detail of intrinsic semiconductors and extrinsic semiconductors
2. Describe the operation of P-N junction diode
3. Draw and explain the forward and reverse bias characteristics of PN junction diode.
Also explain the temperature effects on the characteristics.
4. Describe the energy band structures of an insulator, a metal and semiconductor in
detail
5. What is meant by N-type and P-type semiconductor?
6. Describe in detail about the Effect of temperature on diode operation?
7. Describe in detail about the Static and Dynamic resistances
8. What is meant by transition and Diffusion capacitances?
9. Describe in detail about the Diode switching times.
10. Describe in detail about Atomic theory
.UNIT II
PART A
1. What do you understand by thermal runaway
2. Which transistor configuration will give more bandwidth
3. what is meant by Q-point
4. What is the relation between IB, IE and Ic in CB configuration
PART B
1. Draw and explain the switching characteristics of BJT
2. Explain the different types of biasing method with a neat diagram.
3. Draw and briefly explain the collector current compensation and thermistor
compensation circuits in a transistor
4. What is meant by biasing a transistor?
5. What is the difference between bias compensation and stabilization?
6. Draw a circuit diagram of CE transistor amplifier using emitter biasing. Describe
qualitatively the stability
action of the circuit
7. Explain the working of NPN and PNP transistor by drawing the diagram with
current flow.
UNIT III
PART A
1. Why thermal runaway is not encountered in FET
2. How does a UJT differ from F5. Define pinch off voltage in FET
3. Differentiate JFET and MOSFET
4. Why a field effect transistor is called so?
5.Define the pinch off voltage.
PART B
1. Explain the construction of N- channel MOSJFET with a neat diagram and symbol
2. Explain the construction , working principle of N-CHALLEL depletion MOSFET
3. Explain the various parameters of JFET
4. Explain the self bias circuit of A JFET.
5. With the help of neat sketches and characteristics curves explain the operation of
the JFET.
6. with the help of suitable diagrams explain the working of different types of
MOSFET.
7. With the help of neat diagrams, explain the operation and characteristic of N
channel depletion type MOSFET.
UNIT IV
PART A
1. Draw the VI characteristics of DIAC.
2. Define rectification efficiency and state its value for half wave rectifier
3. Draw the V-I characteristics of a UJT
4. Sketch typical SCR forward and reverse characteristics
PART B
1. Explain the construction, principle of operation and characteristic of SCR
2. Describe the working of FWR with inductive filter and draw its ripple factor
3.
With neat diagram, explain the construction working characteristics of
unijunction characteristics. Give its equivalent circuit.
4. Draw the circuit of a shunt voltage regulation and explain its operation.
5. Explain the operation and characteristics of TRIAC
6. Explain the operation and characteristics of SCR
UNIT V
PART A
1. Sketch characteristics for a phototransistor
2.Draw the energy bond diagram of a tunnel diode.
3. Draw the symbol and equivalent circuit of a varactor diode
4. What are the important characteristics of opto coupler
5. What is a rectifier? what are its types
6. What is the principle of photoconductive cells
PART B
1. Explain the principle of Varactor diode and list out its applications.
2. Sketch the typical construction and illumination characteristics of a photo
conductive cell. Explain its operation.
3. Define tunnelling phenomenon. Explain how tunnel diode operates under
different operation conditions. In what way it is different from the conventional
diodes ? give the necessary energy level diagrams.
4. Explain the construction and working principle of any one type of LCD in
detail. Mention the application of LCD.
5. .Explain the construction and working principle of Zener diode
6. Explain the construction and operation of LED with a neat circuit.