Electronics Devices and Circuits Past Paper 2022 PDF - December Exam

## Paper / Subject Code: 51222 / Electronics Devices and Circuits ### QP CODE: 10014063 **Time: 3 Hours** **Date: 23/11/2022** **Max. Marks: 80** ### Q1 Q1 is compulsory. Attempt any three from Q2 to Q6. **Solve any Four: 5 marks each** * **A**: Explain the operation of a semiconductor pn juncti...

## Paper / Subject Code: 51222 / Electronics Devices and Circuits ### QP CODE: 10014063 **Time: 3 Hours** **Date: 23/11/2022** **Max. Marks: 80** ### Q1 Q1 is compulsory. Attempt any three from Q2 to Q6. **Solve any Four: 5 marks each** * **A**: Explain the operation of a semiconductor pn junction diode with the help of VI characteristics. * **B**: Explain Miller's capacitance theorem. * **C**: Compare BJT CE amplifier and JFET CS amplifier. * **D**: What is crossover distortion in Class B power amplifiers? * **E**: Let VDD = 5V, Vt,1 = 1V, kn,1' = 20µA/V² and R = 1ΚΩ. What should be (W/L)1 needed for creating Iref = 1mA? What should be (W/L)2 if I = 7mA? Refer Fig. 1 ### Q2 **Design a feedback bias circuit for n-channel E-MOSFET with operating drain current of 0.5 mA: 10 marks each** * **A**: Given: VDD = 5 V, k’n = 100 μA/V², W = 1.8 µm, L = 180 nm, Vton = 1 V, Use a standard resistor value for Rp and recalculate ID and VD. Refer fig. 2. ### Q3 * **A**: Explain construction and working of n-channel E-MOSFET: 5 marks * **B**: What is thermal runaway and how it can be avoided?: 5 marks * **C**: Calculate low cutoff frequencies due to coupling and bypass capacitors of the circuit given in fig. 4: 10 marks ### Q4 * **A**: Determine fL and fH for the given circuit. Assume IE = 1.65 mA. Refer Fig 4: 5 marks * **B**: Draw a small signal equivalent circuit of an E-MOSFET CS amplifier given in fig. 3 and derive the expression for voltage gain, input resistance and output resistance. ### Q5 * **A**: Design a voltage divider bias circuit to operate at the given conditions. Calculate the stability factors S(ICO), S(VBE), S(β). Refer Fig. 6: 10 Marks * **B**: Determine the input impedance, output impedance, voltage gain and current gain for the given circuit. Refer fig. 7: 10 Marks ### Q6 * **A**: Derive the equation of CMRR for the MOS differential pair amplifier: 10 Marks * **B**: Write short note on: * **i**: E-MOSFET as a differential amplifier: 5 Marks * **ii**: Zener diode as a voltage regulator: 5 Marks ## Page 1 of 4 ## Paper / Subject Code: 51222 / Electronics Devices and Circuits ### QP CODE: 10014063 * **A**: Draw and explain high frequency model for BJT in CE configuration: 5 marks * **B**: Draw and explain a series fed class A power amplifier with the help of neat diagram and waveforms and derive the expression of power efficiency: 10 Marks ## Page 2 of 4 ## Paper / Subject Code: 51222 / Electronics Devices and Circuits ### QP CODE: 10014063 ## Page 3 of 4 ## Paper / Subject Code: 51222 / Electronics Devices and Circuits ### QP CODE: 10014063 ## Page 4 of 4