ELECTRONIC DEVICES AND CIRCUITS EI2203 QUESTION BANK ANNA UNIVERSITY | EI 2203 EDC ANNA UNIVERSITY QUESTION BANK


ELECTRONIC DEVICES AND CIRCUITS - (EI2203) ANNA UNIVERSITY QUESTION BANK
UNIT I
PART A
1. What is drift current?
2. What is diffusion current?
3. What is p-n junction? Explain the formation of depletion region in unbiased p-n junction.
4. Explain the operation of forward biased diode.
5. Explain the effect of the barrier potential in a forward biased diode.
6. Explain the operation of reverse biased diode.
7. Explain the breakdown mechanisms in a reverse biased diode.
8. Explain the V-I characteristics of a diode.
9. Define forward static and dynamic resistances of diode.
10. Draw and compare V-I characteristics of Ge and Si diodes.
11. Explain the current components in a p-n junction diode.
12. State the diode current equation explaining the meaning of each term involved in it.
13. Derive the V-I characteristics from the current equation of diode.
14. How does the reverse saturation current of diode vary with temperature? Explain.
15. Give  the relation between voltage and current for a p-n junction diode.
16. Write the two types of capacitances associated with a diode.
17. What is diffusion capacitance? State its significance.
18. Write a note on diode switching time.
19. Explain the term transition capacitance C T   of a p-n junction diode.
20. Discuss about avalanche breakdown and zener breakdown.
21. Define intrinsic semiconductors and extrinsic semiconductors.
22.  What is the difference between intrinsic and extrinsic semiconductors.
23. Define the terms Depletion layer, Doping.
24. Why is silicon preferred to germanium in the manufacture of semiconductor devices?
25. How many valence electrons will a perfect conductor, semiconductor and insulator will        have?
26. What are the four different regions in the transistor characteristics? Draw and mention.
27. Draw the symbols of NPN and PNP transistors.
28. What is meant by early effect?
29. In BJT why base area is less and collector area is more?
30. In BJT why base is lightly doped and emitter is highly doped?
31. Draw the two-diode analogy of the transistor and explain why it cannot be used as a    transistor.
32. Draw the input and output characteristics of a BJT.

PART B
1. Discuss about the capacitance effect of a reverse biased p-n junction diode. State its    importance.
2. Write short notes on transition capacitance and diffusion capacitance of a diode.
3. Describe the operation of the p-n junction diode with V-I characteristics.
4. Discuss the forward and reverse biasing  behaviour of a diode.
5. Explain briefly the varactor and schottky diode.
6. Explain the operation of a tunnel diode with its energy band diagram and characteristics.
7. Explain the different current components in a p-n junction diode and hence derive the current equation.
8. Explain the operation of a zener diode and discuss its V-I characteristics. Also discuss zener diode as a voltage regulator .
9. With a neat diagram explain the construction and operation of a BJT showing all the       current components.
10. Sketch the typical input and output characteristics of a common emitter BJT configuration and explain.
11. Sketch the typical input and output characteristics of a common base  BJT configuration and explain.

12. Sketch the typical input and output characteristics of a common collector  BJT configuration and explain.

13. Describe the current components of a NPN and PNP transistor.
14. Explain transistor as a switch and as an amplifier.
15. Explain the terms :
a) Need for biasing
b) D.C load line
c) A.C  load line
d) thermal run away
e) stability factor
16. Discuss the various methods of transistor biasing.

UNIT II
PART A
1. Name the special features of a FET.
2. Draw the symbols of n-channel and p-channel JFET.
3. What are the three JFET parameters?
4. What is the disadvantage of JFET compared to BJT?
5. What is meant by current controlled device and voltage controlled device? Give examples
6. What do you understand by unipolar and bipolar device? Give examples.
7. Which device is called as unipolar explain.
8. Explain the terms Pinch off and IDSS in a JFET.
9. Write the Drain current equation for a JFET.
10. Draw the transfer and drain characteristics of a JFET.
11.What is a MOSFET? How many types of MOSFET are there?
12.How does the constructional feature  of a MOSFET differ from that of a JFET?
13.Give the current – voltage relationships of the N-MOSFET and P-MOSFET.
14.Why is N-channel MOSFET preferred over P-channel MOSFET?
15. What are the difference between UJT and BJT?
16. What is intrinsic standoff ratio in a UJT?
17. Draw the equivalent circuit of a UJT.
18. Draw the V-I characteristics of UJT and mark the three regions of operation.
19. What do you mean by regeneration in UJT?
20. Explain the terms peak voltage and valley current in a UJT.
21. What is meant by negative resistance region in a UJT?
22. Mention two applications of UJT.
23. What is a thyristor? Mention some of them.
24. Draw the symbol of UJT and SCR.
25. Draw the two transistor equivalent circuit of a SCR.
26. Define holding current in a SCR.
27. Draw the V-I characteristics of a SCR.
28. State any two applications of SCR.
29. Explain why a SCR is operated only in the forward biased condition.
31. Explain how triggering of an SCR can be controlled by the gate signal supplied.
32. DIAC is a bi-directional device. Explain?
33. Draw the volt-ampere characteristics of a TRIAC.
34. Draw the transistor equivalent circuit of a TRIAC.
35. Draw the V-I characteristics of a DIAC.
36. Draw the symbol of DIAC, TRIAC.

PART B
1. Explain the construction and operation of a n-channel and p-channel junction field effect transistor.
2. (a) Draw the Drain and transfer characteristics of a JFET and explain.
    (b) Discuss the advantages of JFET over BJT.
3. Explain the operation of UJT relaxation oscillator with a neat diagram.
4. Explain the construction, operation and characteristics of UJT.
5. Discuss in detail with neat sketches the two methods of turning on  and off the SCR.
6. Sketch the construction of a silicon controlled rectifier. Also, sketch the  two-transistor equivalent circuit and show how it is derived from the SCR construction. Label all the terminals and explain how the device operates.
7. Sketch typical SCR forward and reverse characteristics. Identify all the regions of the characteristics and all important current and voltage levels. Explain the shape of the characteristics in terms of the SCR two-transistor equivalent circuit.
8. Draw sketches to show the construction, equivalent circuit and characteristics of a TRIAC. Identify all important voltage and current levels on the characteristics and explain the operation of the device.
9. Draw the typical characteristics of a DIAC. Explain the DIAC operation and sketch the two circuit symbols used for the device.
10. (a) Compare the properties of BJT and FET
 (b) Explain the terms intrinsic stand off ratio, negative resistance region,  peak voltage and valley voltage.
11. With the help of suitable diagrams explain the working of different types of MOSFET.
13. What is channel length modulation in MOSFET? Obtain the output resistance at the Q-point.
14. Draw two biasing circuits for a JFET or a depletion type MOSFET.
15. Draw two biasing circuits for a enhancement type MOSFET.




UNIT III
PART A
1.   Write a note on two port devices.
2.   Explain briefly the term network parameters.
3.   What are h-parameters? Explain.
4.   What are the notations used in transistor circuits for h-parameters?
5.   Explain the hybrid model for two port network.
6.   What is current gain or current amplification factor,A?
7.   What is a R-C coupled amplifier?
8.   What is middle frequency range or mid band of a R-C coupled amplifier?
9.   Explain about the high and low frequency range for a R-C coupled amplifier.
10. What are power amplifiers?
11. What are the types of power amplifiers?
12. What is a class A amplifier?
13. What is a class B amplifier?
14. What is a class AB amplifier?
15. What is a class C amplifier?
16. What is a push-pull amplifier?
17. What is a complementary symmetry push-pull amplifier?
18. What is the power output of a push-pull amplifier?
19. Draw  a class A amplifier.
20. Draw a class B amplifier.
21. Draw a class AB amplifier.
22. Draw a class C amplifier.
23. Draw a push-pull amplifier.
24. Draw a complementary symmetry push-pull amplifier.
25. Explain about the efficiency of a complementary symmetry push-pull amplifier?
26. What is cross over distortion of a push-pull amplifier?
27. Discuss about the various two port parameters.
28. What is known as the operating Power Gain,Ap?
29. List out the characteristics and applications of common base amplifiers.
30. List out the characteristics and applications of common emitter amplifiers.
31. List out the characteristics and applications of common collector  amplifiers.

PART B

1.   Draw the hybrid model for the transistor in three different configurations.
2.   Explain the analysis of a transistor amplifier circuit using h-parameters.
3.   Explain the following the terms:
a)   input impedence,Zi
b)   output admittance,Av
c)   voltage amplification factor,Yo
d)   current amplification factor, A
4.   Draw and explain the simplified h-parameter model of a common base amplifier.
5.   Draw and explain the simplified h-parameter model of a common emitter amplifier.
6.   Draw and explain the simplified h-parameter model of a common collector amplifier.
7.   Explain the operation of a R-C coupled amplifier.
8.   Explain the operation of a two stage R-C coupled amplifier.
9.   Explain the circuit diagram and the working principle of a class A amplifier.
10. Explain the circuit diagram and the working principle of a class B amplifier.
11. Explain the circuit diagram and the working principle of a class AB amplifier.
12. Explain the circuit diagram and the working principle of a class C amplifier.
13. Write the operation of a push-pull amplifier.
14. Explain  the operation of a complementary symmetry push-pull amplifier?
15. Discuss about the various distortions in transistor amplifiers.



UNIT IV

PART A
1. What is the need for feedback in amplifers?
2. Explain the terms feedback factor and open loop gain.
3. What are the types of feedback?
4. Explain the term negative feedback in amplifiers.
5. What are the disadvantages of positive feedback?
6. When will a positive feedback amplifier circuit be unstable?
7. Compare negative feedback and positive feedback.
8. How does negative feedback reduce distortion in an amplifier? Circuit.
9. Explain what type of feedback has been used in an emitter follower.
10. What is the sensitivity of an amplifier?
11. What type of input terminal connections should be used to have a large input impedance?
12. Explain the main difference between an  amplifier and an oscillator.
13. What are the constituent parts of an oscillator?
14. State and explain Barkhausen criterion for oscillation.
15. Write down the expression for frequency of oscillation in Hartley and Colpitts oscillators.
16. Draw the Colpitts oscillator.How are the feedback requirements met in it?
17. Describe the construction of phase shift oscillator.
18. Why do we need three R-C networks for a phase shift oscillator ? Can we have two or four?
19. What are the merits and demerits of a phase shift oscillator?
20. Draw the circuit diagram of a Wien Bridge oscillator.
21. What are advantageous feature of a crystal oscillator?
22. What are the factors which affect the frequency stability of an oscillator?
23. Show the gain of Wein bridge oscillator using BJT amplifier must atleast 3 for the oscillations to occur.
24. What are the main classification of oscillators?
25. What are the essential conditions for maintaining oscillations?
26. What is a sinusoidal and relaxation oscillator?
27. What is a feedback oscillator ?
28. What is a negative resistance oscillator?
29. Classify the oscillator according to the frequency.
30. Classify the oscillator according to the type of circuit used.

PART B
1. Explain with circuit diagram a negative feedback amplifier and obtain an expression for its closed loop gain.
2. Enumerate the effects of negative feedback on various characteristics of the amplifier.
3. Describe with necessary derivations the effect of negative feedback on the bandwidth and distortion in an amplifier.
4. What are the different types of negative feedback?Explain how the input and  output  impedances are  affected by the different types of negative feedback.
5. Explain the negative feedback with the help of the emitter follower as an example . Why is the emitter follower called so?
6. What is the effect of a voltage series negative feedback in the following performance measures of a BJT amplifier?
a)Input resistance
b)Output resistance
c)Bandwidth
d)Distortion and noise
e)Gain stability
7. Draw the circuit diagram of a general oscillator and obtain the maintenance condition and the frequency of oscillations.
8. Draw the circuit of Hartley oscillator and explain its working. Derive the expressions for frequency of oscillation for starting of oscillation.
9. Draw the circuit of Colpitts oscillator and explain its working. Derive the expressions for frequency of oscillation for starting of oscillation.
10. Draw the circuit of R-C phase shift  oscillator and explain its working. Derive the expressions for frequency of oscillation for starting of oscillation.
11.Draw the circuit of Crystal oscillator and explain its working. Derive the expressions for frequency of oscillation for starting of oscillation.
12. Draw the circuit of Wein Bridge oscillator and explain its working. Derive the expressions for frequency of oscillation for starting of oscillation.
13. Derive an expression for the frequency of oscillation and the minimum gain required for sustained oscillation of the R-C phase shift oscillator.
14. Discuss the conditions and considerations for the oscillations with a neat block diagram.
15. Discuss the construction of Quartz Crystal with proper diagrams.


UNIT V
PART A
1.What are RC waveform shaping circuits?
2.What is a low pass RC circuit?Explain its feature and use.
3.How  a high pass RC circuit can be used as a differentiator?
4.How a low pass RC circuit can be used as an integrator?
5.What is a clipper?
6.What is a clamper?
7.What is a multivibrator?
8.On what basis are the multivibrators are classified?
9.Draw the switching waveform for the astable multivibrator.
10.List the applications of astable multivibrator.
11.Which multivibrator  will function as a time delay unit ?Why?
12.List the applications of  bistable multivibrator.
13.How Schmitt trigger is different from a multivibrator?
14.Explain the lower and upper threshold voltages in a Schmitt trigger.
15.What is meant by hysteresis voltage in a Schmitt trigger?
16.List the applications of a Schmitt trigger.
17.Under what conditions  would a Schmitt trigger circuit operate as an amplifier?
18.What is an UJT?
19.Define the intrinsic stand-off ratio of a UJT.
20.Mention some applications of UJT.
21.Explain the terms peak point voltage and valley point voltage.
22.Explain the difference between UJT and a conventional BJT.
23.What are single and poly phase rectifiers?
24.what is a half wave and full wave rectifier?
25.Explain a bridge rectifier.
26.What is transformer utilisation factor?
27.What is peak factor?
28.What are the advantageous of bridge rectifiers?
29.What are polyphase rectifiers?
30.What is the need of filters in power supplies.
31.Explain the various types of filters used in power supplies.
32.Compare the performance of inductive,L-section filters and pi-filters.
33.What are the factors determining the stability of voltage regulators?
34.What is line regulation and load regulation?
35.What is a switch mode power supply?
PART B
1.Draw the responses of high pass and low pass RC circuits to the step and pulse inputs.
2.With the help of circuit diagram and waveforms describe the operation of positive and negative clipper.
3.Describe the operation of biased clipper and combination clipper.
4.Explain the operation of a clamper with the help of necessary circuit diagrams and waveforms.
5.Differentiate between positive and negative clamper.
6.With a neat sketch explain the working of an astable multivibrator.On what factors does the frequency of the output waves depend?
7.What is a monostable multivibrator? Explain its  working with the help of waveforms.
8.With the neat sketch explain the operation of a bistable  multivibrator.
9.Draw the Schmitt trigger circuit  and explain with waveforms.
10.Draw the equivalent circuit of UJT and explain its operation with the help of emitter characteristics.
11.Explain the V-I characteristics of a UJT.
12.Explain how UJT is used as a saw tooth oscillator with proper circuit and graphs.
13.Explain the half wave rectifier with its circuit diagram and characteristics.
14.Explain the full wave rectifier with its circuit diagram and characteristics.
15.Explain the bridge rectifier with its circuit diagram and characteristics.
16.Explain a polyphase rectifier with its circuit diagram and characteristics.
17.Explain the inductive filter with its circuit diagram and characteristics. Also derive an expression for ripple factor.
18. Explain the capacitor filter with its circuit diagram and characteristics. Also derive an expression for ripple factor.
19.Explain the L-section filter with its circuit diagram and characteristics. Also derive an expression for ripple factor.
20. Explain the pi-type filter with its circuit diagram and characteristics. Also derive an expression for ripple factor.
21.Design a zener voltage regulator.
22.Design a transistor series voltage regulator.
23.explain the operation of SMPS in detail with a block diagram.
24.What are the two methods of conversion techniques used in SMPS? List the advantages of SMPS.
25.Obtain the ripple factor  of a full wave rectifier with shunt capacitor filter.






















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y am i not able to copy paste it.????

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