Here is the complete, systematically categorized question bank based on the exam papers provided (2015–2025).
The questions have been extracted exactly verbatim, maintaining every equation, figure reference, and mark. Questions with identical wording are grouped together across years, while similar but non-identical questions remain separated to ensure high-fidelity trend analysis as requested.
1. Tuned Amplifiers
| Subtopic / Subsubtopic | Exact Question + [Marks] + (Figure/Graph ref) | Year(s) of Appearance |
|---|---|---|
| Basic Concepts & Definitions | Define tuned amplifier. Explain the tuned amplifier circuit with its applications. | 2017, 2019 |
| What do you mean by tuned amplifier? Why tuned amplifier is not suitable for audio frequency amplification? | 2018 | |
| Define tuned amplifier. Why tuned amplifier is not suitable for audio frequency amplification? | 2022 | |
| Define tuned amplifier? Why tuned amplifier is not suitable for audio frequency amplification? | 2024 | |
| Define tuned amplifier? Why is tuned amplifier not suitable for audio frequency amplification? | 2025 | |
| What is tuned amplifier? When does the tuned circuit behave like resistive, capacitive, and inductive? | 2023 | |
| Why tuned circuits are not used to amplify low frequencies? | 2017 | |
| Resonance Circuits & Q-Factor | Explain the LC parallel resonance circuit. Draw the phase diagram of a parallel resonance circuit and prove that resonance is occurred when the circuit power factor is unity. | 2015 |
| Explain the LC parallel resonance circuit. Draw the phase diagram of a parallel resonance circuit and prove that resonance is occurred when the circuit power is unity. [06+08] | 2016 | |
| Briefly discuss parallel resonance circuit. Draw the phase diagram of a parallel resonance circuit and prove that resonance is occurred when the circuit power is unity. | 2018 | |
| What are the characteristics of a parallel resonance circuit? Derive the expression for resonance frequency of a parallel circuit. | 2019 | |
| Derive the expression of resonant frequency for a parallel circuit. Explain the characteristics of parallel resonant circuit. Prove that resonance is occurred when the circuit power factor is unity. | 2020 | |
| Briefly discuss parallel resonance circuit. Draw the phasor diagram of a parallel circuit and derive the equation of resonance frequency . | 2022 | |
| Deduce the relationship of the resonance frequency with the inductance and capacitance of a parallel LC circuit. | 2025 | |
| What do you mean by quality factor, Q? Graphically show that smaller resistance provides higher quality factor. | 2015 | |
| What do you mean by Q factor? What is the effect of the Q on the resonance curve? | 2016 | |
| Define Q-factor. Graphically show that smaller resistance provides higher quality factor. | 2018 | |
| Define Q-factor. Graphically show that smaller resistance provides higher Q-factor. | 2022 | |
| Define Q-factor. Graphically show that smaller resistance provides higher Q-factor. | 2023 | |
| Why quality factor is kept as high as possible in tuned circuits? | 2023 | |
| Why quality factor is kept as high as possible in tuned circuits? | 2024 | |
| Graphically prove that the bandwidth of a tuned circuit is proportional to the resistance of inductor and selectivity is inversely proportional to the resistance of inductor. | 2016 | |
| Graphically prove that bandwidth of a tuned circuit is proportional to the resistance of inductor and selectivity is inversely proportional to the resistance of the inductor. | 2019 | |
| Single Tuned Amplifiers | Explain the ac equivalent circuit of a single tuned amplifier in terms of the three input frequency conditions, i.e., (i) , (ii) , and (iii) . Here, the symbols have their usual meanings. | 2017 |
| Define tuned amplifier. Explain the ac equivalent circuit of the tuned amplifier using necessary diagrams. | 2021 | |
| Analyze the gain of a single tuned amplifier in terms of three input frequency conditions, i.e., (i) , (ii) , and (iii) . Here, the symbols have their usual meanings. | 2021 | |
| Analyze the gain of a single tuned amplifier in terms of three input frequency conditions, i.e., (i) , (ii) , and (iii) . Here, the symbols have their usual meanings. | 2022 | |
| Draw the AC equivalent circuit of single tuned amplifier and analyze the gain of a single tuned amplifier in terms of three input frequency conditions, i.e., (i) , (ii) , and (iii) . Here, the symbols have their usual meanings. | 2023 | |
| Draw the equivalent AC circuit of the single tuned amplifier and analyze the gain of a single tuned amplifier in terms of three input frequency conditions, i.e. (i) and (ii) and (iii) . Here the symbols have their usual meanings. | 2024 | |
| Draw the frequency response of an ideal tuned amplifier and discuss its characteristics. | 2023 | |
| Double Tuned Amplifiers | Define tuned amplifier. Write down the differences between single tuned-amplifier and double tuned amplifier. | 2015 |
| What are the differences between the single tuned amplifier and double tuned amplifier? How does the selectivity of a double tuned amplifier depend on the types of coupling? Explain it graphically. | 2017 | |
| Explain different types of coupling of double tuned amplifier. Graphically show that loose coupling provides better frequency response than tight coupling. | 2015 | |
| Explain the operation of double tuned amplifier. Also, graphically show that loose coupling provides better frequency response than tight coupling. | 2018 | |
| Explain the effect of coupling in a double tuned amplifier. Graphically show that lose coupling provides better frequency response than the tight coupling. | 2021 | |
| Explain the effect of coupling in double tuned amplifier. Graphically show that lose coupling provides better frequency response than the tight coupling. | 2023 | |
| Explain the operation of a double tuned amplifier. Why does the name of the amplifier is double tuned amplifier? | 2019 | |
| How does coupling effect the frequency response of a double tuned amplifier (DTA)? Mention the advantages of DTA. | 2025 | |
| Mathematical Problems | For the tuned amplifier shown in Fig. 1(d) below, determine: i) resonant frequency, ii) the Q of tank circuit and iii) bandwidth of the amplifier. (Refer to Fig. 1(d)) | 2015 |
| It is desired to obtain a bandwidth of 250 kHz at an operating frequency of 10 MHz using a double tuned circuit. What value of co-efficient of coupling should be used? | 2016 | |
| What value of co-efficient of coupling should be used to design a double tuned amplifier circuit to obtain a bandwidth of 250 kHz at an operating frequency of 10 MHz? | 2021 | |
| What is the value of coupling coefficient should be used to design a double tuned amplifier circuit to obtain a bandwidth of 250 kHz at an operating frequency of 10 MHz? | 2024 | |
| The dynamic impedance of a parallel resonant circuit is 500k. The circuit consist of a 250pF ccapacitor in parallel with a coil of resistance 100. Calculate (i) the coil inductance, (ii) the resonant frequency and, (iii) Q-factor of the circuit. | 2017 | |
| The dynamic impedance of a parallel resonant circuit is 500 k. The circuit consist of 250 pf capacitor in parallel with a coil of resistance 100 . Calculate: (i) the coil inductance, (ii) the resonant frequency, and (iii) Q-factor of the circuit. | 2020 | |
| A parallel resonant circuit has a capacitor of 100pF in one branch and inductance of 100H plus a resistance of 10 in parallel branch. If the supply voltage is 10V, calculate (i) resonance frequency; (ii) impedance of the circuit and line current at resonance. | 2018 | |
| A parallel resonant circuit has a capacitance of 100 pF in one branch and inductance of 100 H plus a resistance of 10 in parallel branch. If the supply voltage is 10V, calculate (i) resonance frequency, (ii) impedance of the circuit and line current at resonance. | 2019 | |
| A tank circuit of tuned amplifier has a capacitance of 0.1F and inductance of 33mH plus a resistance of 25. Determine (i) the resonant frequency; (ii) the Q of tank circuit; and (iii) bandwidth of the amplifier. | 2018 | |
| A parallel resonant circuit has a capacitance of 250 pF in one branch and inductance of 1.25 mH plus a resistance of 10 in the parallel branch. Find (i) resonant frequency, (ii) impedance of the circuit at resonance, (iii) Q-factor of the circuit. | 2022 | |
| A tuned amplifier has parallel LC circuit. One branch of this parallel circuit has a capacitor of 100 pF and the other branch has an inductance of 1 mH plus a resistance of 25 . Determine (i) the resonant frequency and (ii) Q of the tank circuit. | 2023 | |
| An inductor of resistance 10 and inductance 100 mH is in parallel with a 10 nF capacitor. Find: (i) the resonant frequency, (ii) the Q-factor, and (iii) the bandwidth. | 2025 |
2. Oscillators
| Subtopic / Subsubtopic | Exact Question + [Marks] + (Figure/Graph ref) | Year(s) of Appearance |
|---|---|---|
| Fundamentals & Barkhausen Criterion | What is an oscillator? Explain the operation of a tank circuit with neat diagrams. | 2015 |
| What is an oscillator? What are the conditions to work a transistor as an oscillator? | 2016 | |
| What are the requirements to work a transistor as an oscillator? Write down the name of commonly used transistor oscillator circuits. | 2015 | |
| What are the requirements to work a transistor as an oscillator? Write down the name of commonly used transistor oscillatory circuits. | 2018 | |
| What is sinusoidal oscillator? List the requirements to work a transistor as an oscillator. | 2019 | |
| What is sinusoidal oscillator? Write down the requirements to work a transistor as an oscillator. | 2020 | |
| What is sinusoidal oscillator? Write the requirements to work a transistor as an oscillator. | 2023 | |
| What is sinusoidal oscillator? List the required? List the requirements to work a transistor as an oscillator. | 2024 | |
| Explain the principle of oscillatory circuit. What are the conditions of undamped oscillation. | 2021 | |
| Discuss the usage of an oscillator. Describe the main components required for designing an oscillator. | 2021 | |
| Describe the main component required for designing an oscillator. | 2023 | |
| Describe the main components required for designing an oscillator. | 2024 | |
| Define oscillator. What are the advantages of oscillator as a frequency generator? | 2022 | |
| What are the essential parts of a transistor oscillator? Briefly discuss the functions of each part a transistor oscillator. | 2022 | |
| Illustrate the process of generating undamped oscillations from an oscillator. Mention the advantages of using an oscillator as a function generator. | 2025 | |
| Describe the conditions of making undamped oscillations from a tank circuit. | 2018 | |
| Describe the conditions of making undamped oscillations from a tank circuit. | 2022, 2024 | |
| What is Barkhausen criterion? Why is it important for oscillator circuit? | 2016 | |
| What is Barkhausen criterion? Why is it important for oscillator circuit? | 2017 | |
| Give the graphical explanation of barkhausen criterion. | 2018 | |
| LC Oscillators | Draw and explain the operation of a tuned collector oscillator circuit. | 2019 |
| Compare between the Colpitt and Hartley oscillator. | 2020 | |
| Describe the circuit operation and feedback fraction of Hartley Oscillator with necessary diagram. | 2017 | |
| Draw the circuit diagram of Hartley oscillator. Also describe the circuit operation and feedback fraction of Hartley oscillator. | 2022 | |
| Describe the circuit operation and feedback fraction of Colpitts’s oscillator. | 2018 | |
| Describe the circuit operation and feedback fraction of Colpitt oscillator with necessary diagram. | 2023 | |
| Describe the operation and feedback fraction of Colpitt oscillator with necessary diagram. | 2025 | |
| RC Oscillators | Explain the principle of phase shift circuit of a phase shift oscillator. Explain the operation of a phase shift oscillator circuit. [06+06] | 2016 |
| Explain the principle of phase shift circuit of a phase shift oscillator. | 2017, 2018 | |
| Explain the principle of phase shift oscillator. | 2024 | |
| Explain the Wien bridge oscillator. What is the function of tungsten lamp in the Wien bridge oscillator? Also mention the advantages and disadvantages of this bridge oscillator. | 2015 | |
| Explain the operation of Wien bridge oscillator. What is the function of tungsten lamp in the Wien bridge oscillator? List the advantages and disadvantages of Wien bridge oscillator. | 2019, 2024 | |
| What is the function of the tungsten lamp in a Wien Bridge oscillator? | 2025 | |
| Crystal Oscillators | Define piezoelectric crystal. What are the advantages of crystal oscillator over RC oscillator? | 2015 |
| What are the limitations of LC and RC oscillators? Explain the frequency response of crystal. [03+06] | 2016 | |
| Explain the frequency response of crystal. What are the limitations of LC and RC oscillators? | 2017 | |
| Explain the equivalent circuit of crystal. | 2015 | |
| Explain the frequency response of crystal for different frequency ranges. | 2019 | |
| Why crystal oscillators are preferred over LC or RC oscillators? Explain the frequency response of a crystal. | 2021 | |
| Why are crystal oscillators preferred over LC or RC oscillators? Explain the frequency response of a crystal. | 2025 | |
| Relaxation & UJT Oscillators | Explain the operation of UJT relaxation oscillator. | 2017 |
| Explain the operation of UJT relaxation oscillator and derive the equation for the frequency of the generated saw-tooth output. | 2022 | |
| Explain the operation of UJT Relaxation oscillator and derive the equation for the frequency of the generated saw tooth output. | 2025 | |
| Mathematical Problems | Determine the i) operating frequency and ii) feedback fraction for Colpitt’s oscillator shown in Fig 2(d). (Refer to Fig. 2(d)) | 2015 |
| Determine the (i) operating frequency and (ii) feedback fraction for Colpitts oscillator shown in Fig. 2(d). (Refer to Fig. 2(d)) | 2019 | |
| Determine the (i) operating frequency and (ii) feedback fraction for Colpitt’s oscillator shown in Fig. 2(d). (Refer to Fig. 2(d)) | 2022 | |
| Determine the (i) operating frequency and (ii) feedback fraction for Colpitt’s oscillator shown in Figure 3(c). (Refer to Figure 3(c)) | 2024 | |
| What is the frequency of oscillation in following figure? What is the feedback fraction? How much voltage gain does the circuit need to start oscillation. (Refer to Fig.2(d)) | 2017 | |
| In the Wien bridge oscillator shown in Fig. 2(d) below, and . Determine the frequency of oscillations. (Refer to Fig. 2(d)) | 2016 | |
| Consider an inductor of (last two digits of your Roll/4) mH. Choose the capacitor values in a Colpitts oscillator, so that and . | 2020 | |
| A 1 pF capacitor is available. Choose the inductor values in a Hartley oscillator so that f = 1MHz and = 0.2. | 2023 | |
| A 1 mH inductor is available. Choose the capacitor values in a Colpitts’s oscillator so that f = 1 MHz and . | 2025 | |
| The ac equivalent circuit of a crystal has these values: L = 1H, C = 0.001pF, R = 1000 and = 20pF. Calculate and of the crystal. | 2017 | |
| The ac equivalent circuit of a crystal has three values: L = 1H, C = 0.001pF, R = 1000 and = 20pF. Calculate and of the crystal. | 2018 | |
| The ac equivalent circuit of a crystal has three values: L = 1 H, C = 0.001 pF, R = 1000, and = 20 pF. Calculate and of the crystal. | 2022 | |
| The ac equivalent circuit of a crystal has three values: L = 1H, C = 0.001pF, R = 1000 and = 20pF. Calculate and of the crystal. | 2024 | |
| The AC equivalent circuit of a crystal has three values: L = 1H, C = 0.001 pF, R = 100 and = 20 pF. Calculate and of the crystal. | 2025 | |
| The ac equivalent circuit of a crystal has these values: L = 2H, C = 0.01 pF, R = 1000 and = 20 pF. Calculate and of the crystal. | 2019 |
3. Feedback Amplifiers
| Subtopic / Subsubtopic | Exact Question + [Marks] + (Figure/Graph ref) | Year(s) of Appearance |
|---|---|---|
| Feedback Principles & Topologies | Why negative feedback is necessary. What are the advantages of negative feedback? | 2015 |
| Describe how stable the feedback amplifier gain is compared to an amplifier without feedback. | 2018 | |
| Prove that the gain of an amplifier with negative feedback is more stable than the gain without feedback. | 2019 | |
| Prove that the gain stability of an amplifier with feedback is '' times higher than that of the amplifier without feedback. | 2021, 2023 | |
| Why is negative feedback necessary despite the gain reduction? Prove the gain stability of an amplifier with feedback as '' times higher than that of the amplifier without feedback. | 2025 | |
| Classify different feedback connection types. Write down the property of each feedback connection type. | 2019 | |
| Classify different feedback connection types. Write down the property of each feedback connection type. | 2022 | |
| Classify different feedback connection types. Write down the property of each feedback connection type. | 2024 | |
| Effect on Amplifier Parameters | Explain the effect of negative feedback on gain and bandwidth of a feedback amplifier. | 2015, 2017 |
| Why does negative feedback increase the bandwidth of an amplifier? | 2016 | |
| Briefly explain the effect of negative feedback on gain and bandwidth of an amplifier. | 2020 | |
| Briefly explain the effect of negative feedback on the bandwidth of an amplifier. | 2022 | |
| How does negative voltage feedback increase bandwidth of an amplifier. | 2023 | |
| Briefly explain the effect of negative on gain and bandwidth of an amplifier. | 2024 | |
| Prove that the gain of a practical feedback amplifier is inversely proportional to the feedback factor. | 2015, 2016, 2018 | |
| Prove that the gain of a feedback amplifier is inversely proportional to the feedback factor. | 2020 | |
| Explain the reason of nonlinear distortion in feedback amplifier. Prove that the total harmonic distortion of feedback amplifier is lower than that of without feedback amplifier. [05+10] | 2016 | |
| Prove that the total harmonic distortion of feedback amplifier is lower than that of without feedback amplifier. | 2017 | |
| What is nonlinear distortion? Explain nonlinear distortion in feedback amplifier. | 2021 | |
| Describe non-linear distortion and the effect of feedback on it. | 2025 | |
| Input/Output Impedances | Derive the expressions for input impedances of both the voltages-series and voltage-shunt feedback circuits. | 2017 |
| Explain the relationship between the output impedances without feedback amplifier and with voltage series feedback amplifier. | 2016 | |
| Establish the relationship between the input impedance with feedback and input impedance without feedback of a voltage series feedback amplifier. | 2021 | |
| Establish the relationship between the input impedance with feedback and input impedance without feedback of a voltage series feedback amplifier. | 2022 | |
| Derive the expressions for output impedance of voltage series and current series feedback circuits. | 2018 | |
| Derive the expressions for the output impedance of voltage series and current series feedback circuits. | 2021 | |
| Derive the expression of output impedance of a current series feedback amplifier with necessary diagram. | 2019 | |
| Derive the expression of output impedance of a current series feedback amplifier with necessary diagram. | 2023 | |
| Derive the expression of input impedance of a voltage series feedback amplifier with necessary diagram. | 2024 | |
| Mathematical Problems | The overall gain of a multistage amplifier is 140. When negative voltage feedback is applied, the gain is reduced to 17.5. Find the fraction of the output that is feedback to the input. | 2015 |
| The overall gain of a multistage amplifier is 140. When negative voltage feedback is applied, the gain is reduced to 17.5. Find the fraction of the output that is feedback to the input. | 2021 | |
| An amplifier has an open-loop gain A=100,000. A negative feedback of 10dB is applied. Find, i) voltage gain with feedback and ii) value of feedback fraction, . | 2015 | |
| An amplifier has an open loop gain A=100000. A negative feedback of 10 dB is applied. Find: i) voltage gain with feedback, ii) value of feedback fraction, . | 2016 | |
| An amplifier has an open-loop gain A = 100,000. A negative feedback of 10 dB is applied. Find (i) voltage gain with feedback and (ii) value of feedback fraction, . | 2019 | |
| An amplifier is required with a voltage gain of 100 which does not vary by more than 1%. If it is to use negative feedback with a basic amplifier, the voltage gain of which can vary by 20%, determine the minimum voltage gain required and the feedback factor | 2016 | |
| An amplifier is required with a voltage gain of 100 which does not vary by more than 1%. If it is to use negative feedback with a basic amplifier the voltage gain of which can vary by 20%, determine the minimum voltage gain required and the feedback factor. | 2020 | |
| An amplifier has an open-circuit voltage gain of 70db and an output resistance of 1.5k. Determine the minimum value of load resistance so that voltage gain is not more than 67db. | 2017 | |
| Calculate the gain without and with feedback for the FET amplifier circuit of Fig. 4(d) and the following circuit values: , , , and . (Refer to Fig. 4(d)) | 2018 | |
| Calculate the gain without and with feedback for the FET amplifier circuit of Fig.4(d) and the following values: , , , , and . (Refer to Fig. of Q. 4(d)) | 2021 | |
| Calculate the gain without and with feedback for the FET amplifier circuit of Fig. 3(c) and the following values: , , , , and . (Refer to Figure 3(c)) | 2023 | |
| The gain of an amplifier without feedback is 50 whereas with negative voltage feedback, it falls to 25. If due to ageing, the amplifier gain falls to 40, find the percentage reduction in stage gain (i) without feedback and (ii) with negative feedback. | 2022 | |
| An amplifier has a voltage amplification and a fraction of its output is feedback in opposition to the input. If = 0.1 and = 100, calculate the percentage change in the gain of the system if falls 6 db due to ageing. | 2023 | |
| An amplifier has a voltage amplification and a fraction of its output is feedback in opposition to the input. If = 0.1 and = 100. Calculate the percentages change in the gain of the system of falls 6dB due to aging. | 2024 | |
| An amplifier has a voltage amplification and a fraction of its output is fed back in opposition to the input. If and . Calculate the percentage change in the gain of the system if falls 6 dB due to aging. | 2025 |
4. Operational Amplifiers (Op-Amps)
| Subtopic / Subsubtopic | Exact Question + [Marks] + (Figure/Graph ref) | Year(s) of Appearance |
|---|---|---|
| Ideal Characteristics & Architecture | Define: i) Input offset voltage, ii) Input offset current, iii) Slew rate and iv) Input bias current. | 2015 |
| Define CMMR. Explain the use of an op-amp as an integrator. | 2017 | |
| Define CMRR. Explain the use of an op-amp as an integrator. | 2015 | |
| Define slew rate and CMRR of an op-amp. | 2021 | |
| Define slew rate and CMRR of an Op-amp. | 2022 | |
| What is IC? What are the characteristics of an ideal op-amp? | 2016 | |
| Write down the ideal characteristics of an op-amp. Also, explain the four basic building blocks of an op-amp. | 2018 | |
| List the ideal characteristics of an op-amp. Draw and explain the four basic building blocks of an op-amp. | 2021 | |
| List the electrical characteristics of an ideal op-amp. | 2021 | |
| An ideal op-amp has (i) infinite input resistance, (ii) zero output resistance, (iii) infinite common-mode rejection ratio, and (iv) infinite slew rate, write down the benefits of having these characteristics. | 2019 | |
| What is op-amp? Explain the single ended and double ended operations of op-amp. | 2017 | |
| Explain the single ended and double ended operations of op-amp. | 2015 | |
| What is op-amp? Draw and explain the equivalent circuit of op-amp. | 2020 | |
| Define op-am. Draw the equivalent circuit of an op-amp. How can an op-amp act as a switching circuit? | 2024 | |
| Draw and explain (i) Equivalent circuit of an op-amp and (ii) Ideal voltage transfer curve of an op-amp. | 2019 | |
| Describe equivalent circuit and ideal voltage transfer curve of Op-amp. | 2022 | |
| Define Op-Amp. List the ideal electrical characteristics of an Op-Amp. | 2023 | |
| What is offset voltage in Op-Amp? Briefly explain the offset voltage adjustment process. | 2023 | |
| What is offset voltage in Op-amp? Explain the offset voltage adjustment process. | 2025 | |
| Briefly explain the virtual ground of an op-amp. | 2015 | |
| Define Virtual Ground for inverting op-amp amplifier and Virtual short for non-inverting op-amp amplifier. | 2017 | |
| Explain the virtual ground and virtual short concept for an amplifier using op-amp. | 2021 | |
| Basic Configurations & Feedback | Show that the closed loop voltage gain of an non-inverting amplifier is , where the symbols have their usual meaning. | 2015 |
| Prove that the closed loop voltage gain of a non-inverting op-amp amplifier is lower than its open loop voltage gain. | 2018 | |
| Prove that the closed loop voltage gain of a non-inverting op-amp amplifier is lower than its open loop voltage gain. | 2022 | |
| Derive the expression for gain of an op-amp inverting amplifier with necessary diagram. | 2021 | |
| Derive the expression for gain of an op-amp inverting amplifier with necessary diagram. | 2022 | |
| Derive the expression for scaling operation using op-amp inverting configuration. Can multiplication be perform in this configuration? | 2024 | |
| When a non-inverting amplifier is called a voltage follower? Also, mention its benefits. | 2018 | |
| Write down three applications of a noninverting amplifier with negative feedback. Explain the circuit of a voltage follower in this configuration. | 2024 | |
| Distinguish between common mode gain and differential gain of op-amp. | 2019 | |
| Why an open-loop op-amp is not suitable for linear applications? Write down the applications of positive feedback and negative feedback. | 2017 | |
| ”Negative feedback used in op-amp circuit is more practical for linear applications” – justify the statement. Also,write down the applications of using positive feedback. | 2019 | |
| ”Negative feedback in op-amp stabilizes gain but increases bandwidth”- Explain. | 2025 | |
| Draw the equivalent circuit of an op-amp. Discuss on three open loop configurations as high gain amplifier. | 2025 | |
| Integrators & Differentiators | How can an op-amp circuit act as an integrator? Explain using necessary diagram. | 2020 |
| How an op-amp circuit can be modified to act as an integrator? Deduce an expression of the output voltage for that modified circuit to validate that operation. | 2019 | |
| Justify that an op-amp circuit can be modified to act as an integrator. Deduce an expression of output voltage for that modified circuit to validate the operation. | 2021 | |
| Define integrator circuit. Derive the expression of output voltage of an integrator circuit in terms of input voltage. | 2023 | |
| What are the limitation of a basic integrator? How to solve the limitations? Explain. | 2024 | |
| Write the practical problems of basic differentiator circuit. | 2021 | |
| Write the practical problems of a basic differentiator circuit. Explain the process of reducing these problem in practical differentiator circuit with necessary illustrations. | 2023 | |
| Write down the applications of a differentiator. How does an op-amp act as a differentiator? | 2025 | |
| Arithmetic & Other Applications | Explain the differences between i) inverting and differential summing amplifiers and ii) inverting and non-inverting averaging amplifiers. | 2016 |
| Prove that depending on the relationship between the feedback resistor () and input resistors , and of an op-amp circuit can be used as a summing amplifier, a scaling amplifier, or an averaging amplifier. | 2017 | |
| Describe the operation of an averaging amplifier with non-inverting configuration of op-amp. | 2023 | |
| Describe the operation of an averaging amplifier with non-inverting configuration of op-amp. | 2025 | |
| In the same configurations of an inverting and non-inverting amplifier, which one does have high close loop gain? | 2025 | |
| Mathematical Problems | The 741C op-amp having the following parameters is connected as a non-inverting amplifier as shown in Fig. 5(d), with R1 = 1k, RF = 10 k, A = 200,000, Ri = 2M, Ro = 75, fo = 5 Hz, supply voltages = 15V, output voltage swing = 13 V. Compute the values of AF, RiF, RoF, fF and VooT . (Refer to Fig. 5(d)) | 2015 |
| For inverting amplifier of Fig. 5(d), R1 = 470 and = 4.7k. Calculate the values of , , , , and ; where the 741C op-amp having the following parameters: A = 200,000, = 2M, = 75, 5Hz, supply voltage = 15V, output voltage swing = 13V. (Refer to Fig. 5(d)) | 2017 | |
| The 741c is configured as a non-inverting amplifier as shown in the following figure. The following data are given for the circuit; A=400,000; = 470 ; = 33 M; =4.7 K; = 60 ; Supply voltages = 15 V; Maximum output voltage swing = 13V; UGB=0.6 MHz. Compute the closed-loop parameters , , , and . (Refer to Figure of Q. 4(c)) | 2020 | |
| For the circuit shown in Fig. 5(b), assume ideal op-amp unless otherwise mentioned. i) Name the feedback topology and calculate the feedback factor. ii) Calculate Vo/Vi. iii) Assume R2 is replaced by a capacitor; draw the circuit diagram and find Vo(t). (Refer to Fig. 5(b)) | 2016 | |
| Define CMRR. Determine the output voltages of an op-amp for input voltages Vi1=150 V and Vi2=140 V. The amplifier has a differential gain of Ad=4000 and the value of CMRR is i) 100 and ii) . | 2016 | |
| Define CMRR. Determine the output voltages of an op-amp for input voltages and . The amplifier has a differential gain of and the value of CMRR is (i) 100; (ii) . | 2018 | |
| The following specifications are given for the differential amplifier of Fig. 5(d): and , Vx=-1.5 V pp, and Vy=-2 V pp sine waves at 1 kHz. The op-amp is a IC 741C. Calculate i) voltage gain and the input resistance and ii) the output voltage of the amplifier. Assume that the output is initially nulled (=0 V). (Refer to Fig. 5(d)) | 2016 | |
| In the circuit of Fig. 5(d), , , and the op-amp is a 741C. i. What are the gain and input resistance of the amplifier? ii. Calculate the output voltage if and sine wave at 100Hz. (Refer to Fig. 5(d)) | 2018 | |
| For the circuit shown in Fig. 5(d), assume ideal op-amp: (i) Identify the feedback topology, (ii) calculate , (iii) relate closed-loop gain with open-loop gain. (Refer to Fig. 5(d)) | 2019 | |
| Determine the output voltage in a op-amp based differential amplifier. Assume that, the op-amp is LM741, with supply voltage 15V. | 2024 | |
| In the circuit of Fig. 6(d), = 1 second, and the input is a step (dc) voltage, as shown in Fig. 6(d). Determine the output voltage and sketch it. Assume that the op-amp is initially nulled. (Refer to Fig. 6(d)) | 2017 | |
| In the integrator circuit of Fig. 7(d), the input is a sine wave with a peak-to-peak amplitude of 5 V at 1 kHz. Draw the output voltage waveform if =0.1 ms and . Assume that the voltage across is initially zero. (Refer to Fig. of Q. 7(d)) | 2021 | |
| Design a differentiator to differentiate an input signal that varies from 10 Hz to 1 kHz. | 2015 | |
| Design a differentiator to differentiate an input signal that varies in frequency from 10 Hz to about 1 kHz. | 2016 | |
| Design a differentiator to differentiate an input signal that varies from 10Hz to 1kHz. | 2018 | |
| Design a differentiator that will differentiate an input signal with =100 Hz. | 2021 | |
| Design a differentiator that will differentiate an input signal that varies in frequency from 10 Hz to about 1 KHz. | 2022 | |
| Design a practical integrator circuit to properly process input sinusoidal waveforms up to 1 kHz. The input amplitude is 10 mV. | 2023 | |
| Design and draw a circuit diagram with op-amp amplifier of having three input-signals of each , 100Hz to produce an output signal of , 100Hz. | 2018 |
5. Multivibrators and 555 Timers
| Subtopic / Subsubtopic | Exact Question + [Marks] + (Figure/Graph ref) | Year(s) of Appearance |
|---|---|---|
| Multivibrator Principles & Operations | Define multivibrator. With the aid of circuit diagram briefly explain the operation of bistable multivibrator. | 2015 |
| Define multivibrator. Explain the operation of bistable multivibrator using necessary diagrams. | 2017 | |
| Classify multivibrator. Explain the operation of bistable multivibrator with required circuit diagram. | 2019 | |
| Define multivibrator. Describe different classification of multivibrator. | 2022 | |
| Define multivibrator. Classify its different modes. | 2024 | |
| What are the differences between oscillator and multivibrator? Explain operation of transistor astable multivibrator. [03+06] | 2016 | |
| Define multivibrator. With the aid of circuit diagram briefly explain the operation of monostable multivibrator. Also, mention its applications. | 2018, 2023 | |
| What do you mean by speed up capacitor? | 2017 | |
| 555 Timer Operations | Explain the internal block diagram of 555 IC. | 2016 |
| Explain the internal block diagram of 555 IC. | 2017 | |
| Explain the internal block diagram of 555IC. | 2018 | |
| Briefly explain the internal block diagram of 555 IC. | 2020 | |
| Write down the VCO operation of 555 timer with necessary block diagram. | 2019 | |
| How does charging and discharging occur in astable operation of 555 timer? Show that, it ranges from to . | 2025 | |
| How can 50% duty cycle be achieved in astable operation of 555 timer? | 2025 | |
| How 50% duty cycle can be attained using astable multivibrator. Draw the circuit and explain with necessary equations. | 2024 | |
| Mathematical Problems | Design a 555 astable multivibrator to give a pulse repetition frequency (PRF) of 2 kHz and duty cycle 66%. Use V. | 2015 |
| In the circuit of Fig. 7(d). , the output pulse width ms. Determine the value of C. (Refer to Fig. 7(d)) | 2016 | |
| In the following circuit of Fig. 7(d), , the output pulse width . Determine the value of C. (Refer to Fig. 7(d)) | 2018 | |
| In the astable multivibrator of Fig. 7(d), , , and . Determine the positive pulse width , negative pulse width , and free-running frequency . (Refer to Fig. 7(d)) | 2017 | |
| In the astable multivibrator of Fig. 5(c), , , and C=0.1 F. Determine the positive pulse width , negative pulse width , and free-running frequency . (Refer to Figure of Q. 5(c)) | 2020 | |
| In fig. 6(d), , R = 33 K, and C = 0.47 F. (i) what is the minimum trigger voltage that produces an output pulse? (ii) what is the maximum capacitor voltage? (iii) what is the width of the output pulse? (Refer to Fig. 6(d)) | 2019 |
6. Filters
| Subtopic / Subsubtopic | Exact Question + [Marks] + (Figure/Graph ref) | Year(s) of Appearance |
|---|---|---|
| Filter Basics & Advantages | Discuss about order of filter. What are the advantages of active filters over passive filters? | 2015 |
| What do you mean by the order of filter? Write down the advantages of active filter over passive filter. | 2016 | |
| What is meant by order of filter? List the advantages of active filter over passive filter. | 2019, 2023 | |
| What do you mean by the order of filter? Note down the pros and cons of the Butterworth filter. | 2017 | |
| Define filter. Write three advantages of active filters over passive filters. | 2024 | |
| What is cut-off frequency? What are the differences between band-pass and band-stop filters? [02+06] | 2016 | |
| What is cut-off frequency? What are the differences between band-pass and band stop filters? | 2017 | |
| What are meant by 20 dB/decade and 40 dB/decade in the stopband of a filter? Design a low-pass filter at a cutoff frequency of 1 kHz with a passband gain of 2. | 2018 | |
| Filter Equations & Theory | Derive the gain magnitude and phase angle equations of the 1st order low-pass filter. | 2021, 2023 |
| Derive the gain magnitude and phase angle equations for the 1st order low-pass filter. | 2025 | |
| Define: i) transition time, ii) Settling time, iii) Symmetrical triggering, iv) Unsymmetrical triggering, and v) Notch filter. | 2015 | |
| Mathematical Problems & Designs | Design a low-pass filter at a cut-off frequency of 1 kHz with a pass band gain of 2. | 2016 |
| Design a high-pass filter at a cut-off frequency of 1KHz with a passband gain of 2. | 2017 | |
| Design an op-amp based high-pass filter with cut-off frequency of 1 kHz and passband gain of 2. | 2020 | |
| Design a high-pass filter at a cutoff frequency of 1 KHz with a passband gain of 2. Also, plot the frequency response curve by mentioning cutoff region. | 2022 | |
| Design a 20 db/decade low pass filter so that it has a cut-off frequency of 2 kHz and a pass band gain of 1. | 2021 | |
| Design a second order low pass filter at a cutoff frequency of 1.2 KHz. | 2022 | |
| Design a low-pass filter at a cutoff frequency of 1 kHz with a passband gain of 2. Using the frequency scaling technique, convert the 1 kHz cutoff frequency to a cutoff frequency of 1.6 kHz. | 2021 | |
| Design a low-pass filter at a cut-off frequency of 1 KHz with a passband gain of 2. Using the frequency scaling technique, convert the 1 KHz cutoff frequency to a cutoff frequency of 1.6 KHz. | 2022 | |
| Define comparator circuit. Design a low-pass filter at a cutoff frequency of 1 kHz with a passband gain of 2. Using the frequency scaling technique, convert the 1 kHz cutoff frequency of the low-pass filter to a cutoff frequency of 1.6 kHz. | 2023 | |
| Design a wide band-pass filter with , , and a passband gain = 4. | 2019 | |
| Design a wide band-pass filter with , , and a passband gain =4. | 2023 | |
| Design a wide bandpass filter with , and a passband gain=4. Calculate the Q value of the filter. | 2024 | |
| Design a wide bandpass filter with , and a passband gain of 3.5. Calculate the Q-value of the filter. | 2025 | |
| Draw the circuit diagram of a first order active high pass filter and its response curve. | 2021 |
7. Wave Shaping Circuits
| Subtopic / Subsubtopic | Exact Question + [Marks] + (Figure/Graph ref) | Year(s) of Appearance |
|---|---|---|
| Comparators & Detectors | What is comparator? Write down its five basic uses. | 2024 |
| How a comparator circuit can act as a voltage-level detector? Draw a +10V voltage-level detector with op-amp. | 2019 | |
| Explain the operation of window detector and also write down it’s applications. | 2019 | |
| Explain the operation of window detector and also write down its applications. | 2023 | |
| Explain the operation of window comparator circuit with necessary diagram. | 2022 | |
| Schmitt Triggers | What is Schmitt trigger? Describe its input-output response with hysteresis properties. | 2015, 2017 |
| What is Schimit trigger? Describe the input-output response with hysteresis properties. | 2020 | |
| What is the difference between a comparator and Schmitt trigger? Why Schmitt trigger is known as regenerative comparator? | 2016 | |
| What are the differences between a comparator and Schmitt trigger? Why Schmitt trigger is known as regenerative comparator? | 2018 | |
| Explain the operation of Schmitt trigger circuit with necessary diagram. | 2021 | |
| Explain the operation of Schmitt trigger circuit with necessary diagram. | 2022 | |
| ”Schmitt trigger converts an irregular-shaped waveform to a square pulse”- Explain with necessary derivation. | 2025 | |
| Clippers & Clampers Principles | What do you mean by clipping circuit? Give some application of the clipper. | 2015 |
| Define and classify clipper. Why clipper is used in electronic system? | 2016 | |
| What do you mean by clamper circuit? Give some application of the clamper. | 2018 | |
| Write short note on (i) Clipper, and (ii) Clamper. | 2019 | |
| What are meant by clamper and clipper circuit? Mention their common applications. | 2020 | |
| Define clipper and clamper circuits. Draw the output waveforms of the following circuits shown in Fig. 8(a). Assume diodes are ideal. (Refer to Fig. of Q. 8(a)) | 2021 | |
| Mathematical / Graphical Problems | Draw the output waveshapes of the following circuits shown in Fig. 8(c). Consider the diode as an ideal one in each case. (Refer to Fig. 8(c)) | 2015 |
| Draw the output waveshapes of the following clipper circuits. Assume diodes are ideal. (Refer to Fig. 8(c)) | 2016 | |
| Draw the output waveshapes of the following clamper circuits. Assume diodes are ideal. (Refer to Fig. 8(d)) | 2016 | |
| Draw the output wave shapes of the following clipper circuits. Assume diodes are ideal. (Refer to Fig.8(c)) | 2017 | |
| Draw the output waveshapes of the following circuits shown in Fig. 8(c). Consider the diode as ideal one in each case. (Refer to Fig. 8(c)) | 2018 | |
| Draw the output waveshape of the following clipper circuits. Assume diodes are ideal (Refer to Fig. 8(c)) | 2019 | |
| Draw the output waveshape of the following clamper circuits. Assume diodes are ideal. (Refer to Fig. 8(d)) | 2019 | |
| Draw the output wave shapes of the following circuits of Fig. 6(c). (Refer to Figure of Q.6(c)) | 2020 | |
| Draw the output wave shape of the following clamper circuits of Fig. 8(c). Assume diodes are ideal. (Refer to Fig. 8(c)) | 2022 | |
| Draw the output waveforms for the figure 6(b), where input is a sinusoidal wave at 50Hz. (Refer to Figure 6(b)) | 2024 | |
| Calculate (i) upper threshold voltage (ii) lower threshold voltage, and Hysteresis voltage of a Schmitt trigger circuit, given that . | 2024 | |
| Determine the (i) upper threshold voltage, (ii) lower threshold voltage, and (iii) Hysteresis voltage of a Schmitt trigger circuit, given . | 2025 |
8. Phase Locked Loop (PLL)
| Subtopic / Subsubtopic | Exact Question + [Marks] + (Figure/Graph ref) | Year(s) of Appearance |
|---|---|---|
| PLL Concepts & Architecture | What do you know about PLL? With the help of block diagram briefly explain its construction and operating principle. | 2015 |
| What do you know about PLL? With the help of block diagram briefly explain its construction and operating principle. | 2017 | |
| Write a short note about PLL. With the aid of block diagram briefly explain its construction and operating principle. | 2018, 2022 | |
| Write a short note about PLL. With the aid of block diagram briefly explain its construction and operating principle. | 2023 | |
| What is PLL? What are the applications of PLL in communication systems? [04+04] | 2016 | |
| Draw the block diagram of PLL and explain in brief. | 2019 | |
| Draw the block diagram of phase locked loop. | 2022 |