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Table 1: BJT DC Biasing and Stability

Subtopic/ Sub-subtopicQuestionsTypeYear(s)
Load Line AnalysisDefine load line and explain it’s significance. Explain the effect of changing the circuit elements of a fixed bias common emitter circuit on the transistor operating point.Descriptive2023
What is load line? Explain the effects of changing the levels of base current, collector resistance, and Vcc on the transistor operating point (Q) using the load line analysis.Descriptive2017
What is load line analysis? Explain the switching operation of BJT using load line analysis.Descriptive2015
Stability & Thermal RunawayDefine thermal stability in transistor amplifiers. Explain thermal runway and how it can be prevented using bias stabilization techniques.Descriptive/Definition2023
What is meant by thermal runaway? How does thermal runaway change the operating point of an amplifier?Descriptive/Definition2022
Explain the factors that affect the stability of a transistor circuit.Descriptive2022
Explain the factors that affect the stability of a transistor circuit. How does an additional emitter resistance improve the stability? Explain in brief considering the physical happenings.Descriptive2021, 2017
What do you mean by bias stabilization and thermal runway?Definition2019, 2015
How is the operating point of transistor affected by increase of surrounding temperature?Descriptive2018
Write the mathematical expressions of stability factors and hence show that voltage divider bias configuration is the most stable.Descriptive/Mathematical2018, 2015
What is meant by bias stabilization? “The Q-point of a bias circuit become more stable if an emitter resistance is connected” – Justify the statement.Descriptive/Justification2016
Biasing Configurations“Two diodes connected back to back resemble a transistor amplifier”- Explain in brief.Descriptive2023
“Two diodes connected back to back resemble a transistor but it cannot work as a transistor amplifier” – explain.Descriptive2021, 2019
Describe the concept of mid-point biasing.Descriptive2021
What is the necessity of transistor biasing? Design a fixed bias circuit in order to obtain the following load line and Q-point. [Ref Figure 1(a) with , , ]Descriptive/Design2018
What is the necessity of transistor biasing? Design a fixed bias circuit in order to obtain the following load line and Q-point. [Ref Figure 1(a) with , , ]Descriptive/Design2016
What is the condition for approximate analysis of voltage divider bias configuration? Determine the values of and of the following network using approximate analysis. [Ref Figure 1(d)]Descriptive/Calculation2018
Design ProblemsDetermine , and for the emitter bias configuration of shown in figure 2(c).Calculation2023
Given that and , determine and for the network of Fig. 1(d).Calculation2022
Determine the levels of , , and for the network of Fig. 1(d) for the operating point indicated. [Ref Figure 1(d) with , ]Calculation2021, 2019
Design a voltage-divider bias network using a supply of 24V, a transistor with a beta of 110 and operating point of and . Choose .Design2020
Determine the quiescent levels of and for the following network shown in figure 1(d).Calculation2017
Determine and for the following voltage divider network with the operating point of and .Calculation2016
Determine the values of and for the voltage divider configuration of Fig. 1(d).Calculation2015

Table 2: BJT Small Signal Analysis

Subtopic/ Sub-subtopicQuestionsTypeYear(s)
BJT Modeling ConceptsWhat is meant by BJT modeling? Write down the procedure of obtaining ac equivalent circuit of a BJT.Definition/Descriptive2023, 2022, 2018
Expound on the differences between small signal analysis and large signal analysis.Comparison2023
What are the differences between small signal analysis and large signal analysis? What are the procedures of obtaining ac equivalent network of BJT circuits?Comparison/Descriptive2019, 2016
What is the necessity of BJT modelling? Write down the advantages and disadvantages of model.Descriptive/Comparison2017
What do you mean by BJT modeling? Compare model and hybrid model mentioning their advantages and disadvantages.Comparison2015
Model AnalysisDerive the expression for (i) , (ii) , (iii) , and (iv) of common emitter fixed biased configuration in forms of .Mathematical/Derivation2022, 2021, 2019, 2018, 2017, 2016
Elucidate the significance of emitter resistor in emitter bias configuration and explain the effect of a bypass capacitor on the performance of an amplifier.Descriptive2023
What is the significance of emitter resistor in emitter bias configuration? What are the effects of a bypass capacitor on the voltage gain of an amplifier?Descriptive2022, 2020
For the network shown in figure 1(c), determine , , , and considering . Also, determine considering and compare the results.Calculation2023, 2019
Design an amplifier circuit considering the following requirements: (i) Common emitter bias configuration, (ii) Voltage gain, (without bypass), (iii) Stability factor, . Also, explain the impact of bypass capacitor in this amplifier circuit.Design/Descriptive2022
Design an amplifier circuit considering the following requirements: (i) Voltage gain, (without bypass), (ii) Stability factor, . Also, explain the impact of bypass capacitor in this amplifier circuit.Design/Descriptive2021
For the network of the following figure, determine (i) , (ii) and (iii) using approximate analysis. [Ref Figure 2(b)]Calculation2020
For the following network, determine: (i) , (ii) , (iii) , (iv) and (v) considering connected (bypassed) and without (un-bypassed). Also comments on the obtained voltage gain.Calculation/Descriptive2018, 2017
Define -modeling. Draw the -models for common emitter and common collector configuration.Definition/Diagram2016
Find the voltage gain () of the following network with and without the bypass capacitor () and comment on the obtained results.Calculation/Descriptive2016
Write the merits of emitter follower configuration. Using modeling concept, derive the expression for input impedance () and output impedance () for emitter follower configuration.Descriptive/Derivation2015
Determine: (a) , (b) , (c) , and (d) for the following network. [Ref Figure 2(c)]Calculation2015
Hybrid Model Analysis“The input impedance is a function of load impedance” – Justify the statement using the hybrid modeling concept.Justification2022, 2021, 2017
What are the advantages of hybrid model? Draw the exact and appropriate hybrid model of three common configurations.Descriptive/Diagram2021, 2019, 2016
Define hybrid model and hybrid parameters. Draw the hybrid models of three different configurations of transistor.Definition/Diagram2018
Define -parameters. How can you determine -parameters from transistor characteristic curves?Definition/Descriptive2020, 2015
Derive the expression for , , , and for a basic transistor amplifier circuits using -parameters model.Derivation2015
Darlington Pair & MultistageDiscuss the working principle of Darlington pair circuit using necessary diagram.Descriptive2023, 2019
What is Darlington pair circuit? Derive the expression for current gain () of Darlington pair using h-parameters and comments on the obtained expression.Descriptive/Derivation2017, 2015
Derive the expression for current gain () of Darlington pair circuit using h-parameters and comments on the obtained expression.Derivation2018
Determine the input impedance and overall gain of the two-stage amplifier shown in figure 4(b) using simplified model. [Ref parameters , , , ]Calculation2023, 2019, 2015
A two-stage amplifier circuit (CE-CC) is shown in Fig. 3(c). [Ref parameters]. Find the input and output impedances, and overall voltage and current gains of the combined circuit.Calculation2021, 2018
Determine , , , and for the following two-stage cascade network using simplified hybrid model.Calculation2017
Determine the input impedance and overall voltage gain of the following two stage amplifier using simplified hybrid model. [Ref Figure 3(d)]Calculation2016

Table 3: Field Effect Transistors (FETs)

Subtopic/ Sub-subtopicQuestionsTypeYear(s)
BJT vs FET / CharacteristicsWrite down the differences between BJT and FET.Comparison2023, 2017, 2016
Briefly explain the reasons behind the higher input impedance of FET.Descriptive2018
Distinguish between p-channel and n-channel JFET? A p-channel JFET has and . Sketch its transfer characteristics.Comparison/Diagram2019, 2016
JFET Biasing (DC)For a JFET self-bias configuration, prove that , with necessary diagram.Derivation2023, 2015
Determine the following parameters using the given network shown in figure 5(c): (i) , (ii) , (iii) , (iv) , (v) , (vi) and (vii) . [Voltage Divider Bias]Calculation2023
Determine the following parameters in Fig. 5(b): (i) , and (ii) for the following n-channel JFET network with and .Calculation2022, 2019
For the network shown in Fig. 5 (c), determine (i) , (ii) , (iii) , (iv) , (v) , and (vi) .Calculation2021
Explain the voltage divider biasing of FET amplifier and consequently discuss the effect of on the resulting Q-point.Descriptive2021, 2018, 2017, 2015
For the network shown in Fig. 6 (c), determine (i) , (ii) and , (iii) and , (iv) .Calculation2021
Determine (i) , (ii) , (iii) , and (iv) for the common gate configuration shown in Figure 5(b).Calculation2020
For the following network, determine: (i) , (ii) , (iii) , (iv) , (v) and (vi) . [Self-Bias JFET, Fig 6(c)]Calculation2018, 2017, 2015
Write down the differences between self-bias and fixed bias configuration of FET.Comparison2016
For the given network in Fig. 6(d), determine i) , ii) , iii) and iv) . Use appropriate transfer curve for calculation.Calculation2016
JFET AC AnalysisDerive the mathematical definition of transconductance. Explain the effect of drain current on transconductance factor of FET.Derivation/Descriptive2023, 2017
Define transconductance (). Derive the expression of transconductance factor for JFET.Definition/Derivation2020
Give the mathematical derivation of transconductance.Derivation2018, 2016, 2015
Show that ; where symbols have their usual meanings.Derivation2015
Prove that for common gate JFET configurations.Derivation2023, 2021, 2019, 2017
For the network shown in figure 6(c), operating at and , determine (i) , (ii) , (iii) , (iv) , (v) with and without . Also give comments on the effect of on .Calculation/Descriptive2023
Prove that for a self bias FET configuration voltage gain increase when bypass resistance is used.Derivation2023, 2022, 2018, 2016
Derive the expression of voltage gain for self-bias configuration with unbypassed .Derivation2019
For a self-bias configuration of JFET amplifier, show that the voltage gain with unbypassed is less than the voltage gain with bypassed .Comparison/Derivation2015
Design the following fixed biased network to have an ac gain of 10. [Ref Figure 7(c) / 8(c)]Design2022, 2019, 2018, 2015
For the following fixed-bias configuration, Determine: (i) , (ii) , (iii) , (iv) , (v) with and without .Calculation2022
For the network shown in Fig. 7 (c), has an operating point and . With an applied signal , determine (i) , (ii) , (iii) , (iv) , and (iv) .Calculation2021
A dc analysis of the following network (Fig. 6(b)) results in and . Determine (i) , (ii) , (iii) and (iv) without .Calculation2020
Draw a JFET source follower configuration and its ac equivalent circuit. From this circuit, prove that .Diagram/Derivation2019
The source follower network of the following figure has the Q-point as and . Determine: (i) , (ii) , (iii) , (iv) with and without and (v) with and without .Calculation2018, 2017, 2016
Determine the following parameters for the network in Fig. 7(c); (i) , (ii) , (iii) with and without , (iv) with and without and (v) with and without . Also give your comments on the results of (iii) – (v).Calculation/Descriptive2015
MOSFETsConstruct an n-channel enhancement-type MOSFET and explain its basic operation.Descriptive2022
Distinguish between depletion type and enhancement type MOSFET, why is the input impedance of MOSFET so high? Explain in brief.Comparison/Descriptive2021, 2019
What are the differences between enhancement and depletion MOSFET? Explain the construction and operation of depletion type MOSFET using necessary diagrams.Comparison/Descriptive2016

Table 4: Power Amplifiers

Subtopic/ Sub-subtopicQuestionsTypeYear(s)
Concepts & Classification“The efficiency of power amplifier increases with smaller input operating cycle”-Justify the statement with necessary diagrams.Justification/Diagram2023, 2017, 2016, 2015
“Power amplification is mainly a nonlinear process” – justify the statement.Justification2022, 2018, 2015
Distinguish between voltage amplifier and power amplifier.Comparison2021, 2019
What are the key differences between voltage amplification and power amplification concepts? Compare different classes of power amplifiers.Comparison2019
Define and classify power amplifier. Why do uses of smaller input cycle provide larger efficiency in power amplifier?Definition/Descriptive2016
What are the major considerations in designing power amplifier circuits? Explain in brief.Descriptive2018, 2015
Push-Pull AmplifiersDefine crossover distortion. Explain the operation of a transformer coupled push-pull amplifier.Definition/Descriptive2023
Explain the operation of Quasi-Complementary push-pull amplifier. How does this amplifier minimize crossover distortion?Descriptive2022
What is crossover distortion? Explain the operation of transformer coupled push pull power amplifier using suitable diagram.Definition/Descriptive2021
Why is complementary push-pull power amplifier called so? Explain the operation of complementary push-pull power amplifier using suitable diagram.Descriptive2020
Why is push-pull power amplifier called so? Explain the operation of complementary push pull power amplifier using suitable diagram.Descriptive2019
Why is the push-pull power amplifier called so? Deduce the expression for maximum efficiency of push-pull power amplifier.Descriptive/Derivation2018, 2017, 2015
Explain the working principle of complementary power amplifier using necessary diagram.Descriptive2016
Draw the block diagram of a typical class-D power amplifier and briefly explain its operation.Diagram/Descriptive2016
Efficiency & CalculationDesign a class A amplifier for maximum efficiency with the following specification: , , a load resistance of , and a turn ratio of 5.Design2023
For a class B amplifier using a supply of and driving a load of , determine the maximum input power and output power.Calculation2021
Show that the maximum efficiency of push pull power amplifier is 78.5%.Mathematical Proof2019

Table 5: Frequency Response and Miller Effect

Subtopic/ Sub-subtopicQuestionsTypeYear(s)
General ResponseExplain the frequency response of a common emitter amplifier and briefly discuss the impact of various capacitive element on transistor frequency response.Descriptive2023
Determine the lower cutoff frequency for the network for the network of Fig. 3(c) using following parameters: , , , , , , , , , , , .Calculation2022
Explain the low frequency and high frequency responses of a BJT amplifier.Descriptive2020
How is the frequency response varied with number of stages in multistage amplifier? Illustrates graphically.Descriptive/Diagram2019, 2018, 2016
What are the components involved in low and high frequency response of bipolar junction transistor circuits? Find the frequency for each component and explain the overall frequency response using necessary diagram.Descriptive/Calculation2017
Determine the high-cutoff frequencies for the network shown in Fig. 6(c) using the following parameters: , , , , , , .Calculation2022
Determine the lower cut-off frequency for the network shown in Fig. 8(c) using the following parameters. [Ref JFET network].Calculation2016
Miller EffectWhat is Miller capacitance? Write down the effect of Miller capacitance on the high frequency cutoff of BJT circuit.Definition/Descriptive2022, 2021, 2019, 2018, 2016
Define Miller effect.Definition2017

Table 6: Specialized Electronic Circuits

Subtopic/ Sub-subtopicQuestionsTypeYear(s)
Diode CircuitsWrite short note on Clipper and Clamper.Definition/Descriptive2022
Draw the output waveshapes of the following clamper circuits. Assume diodes are ideal. [Ref Figure 6(d) / 8(b)]Diagram2023, 2022
555 Timer & CMOSDescribe the procedure of pulse generation using 555 timer with necessary diagrams.Descriptive/Diagram2023
Explain the operation of a CMOS inverter and mention the advantages of using CMOS technology.Descriptive2023
Design an inverter using CMOS and explain its operation.Design/Descriptive2022
Op-Amp CircuitsDesign a comparator circuit that will identify whether an ac input voltage is higher or lower than 4V.Design2023

Table 7: Display Systems and Optoelectronic Devices

Subtopic/ Sub-subtopicQuestionsTypeYear(s)
CRT & DeflectionProve that deflection on the screen of a Cathode Ray Tube is directly proportional to the deflecting voltage between the plates.Mathematical Proof2022, 2018
Prove that a cathode ray tube may be used as a linear voltage indicating device.Mathematical Proof2021, 2017
“A cathode ray tube may be used as a linear voltage indicating device” – justify the statement.Justification2020, 2018
Show that the electrostatic deflection sensitivity of a cathode-ray tube is , where the symbols have their usual meanings.Mathematical Proof2015
Write short note on electrostatic deflection sensitivity.Definition2019
Write short note on magnetic deflection and its sensitivity.Definition2017
Write down the similarities between electrostatic-deflection sensitivity and magnetic-deflection sensitivity.Comparison2015
Displays (LCD, OLED, etc.)Describe the basic operation of LCD display and write its application.Descriptive2023, 2022
Write the advantages of LCD over CRT. Differentiate between QLED and OLED.Comparison2023, 2022
Write short notes on plasma display technology.Definition/Descriptive2023
What is LCD? Describe the basic operations of LCD panel.Definition/Descriptive2018, 2015
OptoelectronicsDescribe the basic operating principle of a solar cell.Descriptive2021, 2020, 2019
Describe the basic operating principle of a solar cell and write its application.Descriptive2022
Briefly explain the construction and operating principle of solar cell. Also, calculate the maximum power rating of a solar cell if its conversion efficiency is 85%.Descriptive/Calculation2019
Explain the construction and operating principle of a solar cell.Descriptive2015
Describe the operating principle of photo-conductive cells. Also mention some practical applications of photo conductive device.Descriptive2021, 2019, 2018, 2015
What is photodiode? Describe the operation and characteristics of photodiode.Definition/Descriptive2019
Write short notes on (i) Photodiode, (ii) Phototransistor.Definition2015

Table 8: Motion of Charged Particles in Electromagnetic Fields

Subtopic/ Sub-subtopicQuestionsTypeYear(s)
Electric & Magnetic FieldsFor a charged particle placed in a magnetic field, show that the period and angular velocity are independent of speed or radius.Mathematical Proof2020
“For a charged particle placed in a magnetic field, the period and angular velocity are independent of speed or radius?”-Justify the statement.Justification2019
If a charged particle enters to a constant uniform magnetic field normally with a speed, then prove that period and angular velocity will be independent of speed or radius.Mathematical Proof2016
Discuss about the path of a charged particle in presence of parallel electric and magnetic fields.Descriptive2021, 2019, 2017, 2015
Give your comments about the path of a charged particle in presence of parallel electric and magnetic field.Descriptive2016
Show that electron moves in a parabolic path in the region between two parallel plates of a capacitor in presence of electric filed.Mathematical Proof2021, 2017, 2015
Write your idea about radius of circles generated by different particles moving with different initial velocities in a magnetic field.Descriptive2018
Compare electrostatic deflection sensitivity and magnetic deflection sensitivity.Comparison2016
Show that the notion electron in an electromagnetic field can be expressed as: ; ; and ; where the symbols have their usual meanings.Mathematical Proof2016