B.Tech Analog Electronic Circuits Past Paper 2023-2024 PDF

## 3rd Semester Regular/Back Examination: 2023-24 ### Subject: Analog Electronic Circuits ### Branch(s): - AEIE - BIOMED - EEE - ELECTRONICS & C.E - EIE - ELECTRICAL - ECE - ETC - EE - ECE ### Time: 3 Hours ### Max Marks: 100 ### Q.Code: N451 **Answer Question No. 1 (Part-I) which is compulsory,...

## 3rd Semester Regular/Back Examination: 2023-24 ### Subject: Analog Electronic Circuits ### Branch(s): - AEIE - BIOMED - EEE - ELECTRONICS & C.E - EIE - ELECTRICAL - ECE - ETC - EE - ECE ### Time: 3 Hours ### Max Marks: 100 ### Q.Code: N451 **Answer Question No. 1 (Part-I) which is compulsory, any eight from Part-II and any two from Part-III.** **The figures in the right-hand margin indicate marks.** ### Part-I **(2 x 10)** **(a)** What is the significance of pinch off voltage and threshold voltage in MOSFET? **(b)** Discuss about load line in a BJT biasing circuit. **(c)** Explain the roles of different external capacitors used in an amplifier circuit. **(d)** What is a super-beta transistor? Justify. **(e)** Whether the output of a CE configuration is in phase or out of phase with the input? Justify. **(f)** Draw the hybrid and r model of a transistor in CE configuration. Write the difference between them. **(g)** With a neat sketch locate the parasitic capacitances for high-frequency response. Among them which one is largest and which one is smallest? **(h)** Differentiate between small-signal amplifier and large-signal amplifier. What are the advantages and disadvantages of negative feedback in an amplifier? **(i)** How are the class A, B, C amplifiers are defined? Briefly discuss class A type. ### Part-II **(6 x 8)** **(a)** Explain how the transconductance of D-MOSFET is determined both graphically and mathematically? **(b)** Draw and explain the circuits of self-bias and Emitter bias. Write the differences between. **(c)** For a base-biased transistor circuit with Vcc = 30V, RB = 300 ΚΩ, Rc = 2 ΚΩ, RE = 1 ΚΩ and current gain = 100, find the Q-point, Ic(sat), Vc, and Ve. **(d)** What is source-degenerative resistance? Considering this resistance, draw the equivalent model of a CS MOSFET amplifier. Find its input impedance, output impedance, open loop voltage gain and the voltage gain in consideration of the load resistance. **(e)** Explain in detail the effect of Rs and R₁ on BJT low frequency response. **(f)** What is modeling of a device? Draw the re models of all three configurations. Draw the hybrid model of a transistor in CE and derive the expressions for input impedance, output impedance, voltage and current gain. **(g)** Derive the expression of A, and Zo of the self-biased CS MOSFET circuit with un-bypassed Rs. **(h)** What is trans-conductance and overdrive voltage of a MOSFET? Write the relation between trans-conductance and overdrive voltage. Describe in detail, how the T equivalent model of a MOSFET is developed. **(i)** Draw and explain the small signal analysis of JFET CS and CD configuration. **(j)** What is a feedback network? Describe a positive feedback circuit as an oscillator. Explain Barkhausen's criteria for oscillation. **(k)** Explain the operation of an Op-amp as a non-inverting amplifier, a differentiator, and an Integrator. **(l)** Draw and explain the operation of an Instrumentation amplifier. What are the advantages of an Instrumentation amplifier? ### Part-III **(Answer Any Two out of Four)** **(Q3)** With suitable diagrams, describe the operational principle of FETs and MOSFETS. Extend your discussion to V-I Characteristics of E- MOSFET and D-MOSFET. **(16)** **(Q4)** How many biasing circuits are there in a BJT circuit? Explain each of it. Out of all the biasing circuits which one is practically not employed? **(16)** **(Q5)** Which capacitors affect the low frequency and high frequency responses of a BJT amplifier circuit? What is Miller effect capacitance? Describe all in detail. **(16)** **(Q6)** What is a power amplifier circuit? Why is it named so? Explain class A, class B, class AB, and class C power amplifiers providing their efficiencies. **(16)**