#1
| |||
| |||
![]()
I am a student of Punjab Technical University Jalandhar B.Tech ECE-3rd Sem and my exams are near so I want to get the previous years question papers so can you provide me that? As you want to get the previous years question papers of Punjab Technical University Jalandhar B.Tech ECE-3rd Sem so here is the information of the same for you: Previous years question papers of Punjab Technical University Jalandhar B.Tech ECE-3rd Sem 1). a). Discuss the behavior of p-n junction diode under forward and reverse biased conditions. b). Draw circuit diagram for CC and CE configuration of transistor. Which is having higher gain and why. c). State advantages of JFET over BJT. d). What is operating point? Why is it necessary to stabilize operating point of a transistor amplifier? e). What do you understand by class A,B and C power amplifiers. f). Draw the block diagram of a multistage amplifier having n-stages. Write expression for its gain (A). g). State advantages of –ve feedback in amplifiers. h). What is an oscillator? What are the essential components of feed back LC oscillator? i). Differentiate between photo diodes and photo transistor. j). Define term junction capacitance. Name different type of capacitances diode posses. Section-B 2). Define stability factor. Explain with circuit diagram of potential divider method of biasing in amplifiers. 3). Draw the circuit diagram of a push pull amplifier. Explain its operation. Discuss advantages and disadvantages. 4). What do you mean by coupling of two amplifier stages. Explain with requisite circuit diagrams the resistance-capacitance coupling scheme. 5). Draw the block diagram of negative feed back amplifier. Derive an expression for the voltage gains of an amplifier of gain (A) when subjected to negative feedback (B). 6). Explain the principal of working of transistor Hartley oscillator. Draw circuit diagram and briefly function of each component. Section-C 7). Define h-parameters. Derive expression for (a) Voltage gain (b) Current gain (c) Input resistance (d) Output resistance of CE amplifiers using h-parameters 8). (a) Draw labeled diagram showing constructional features of N-channel MOSFET. Explain principle and working of N-channel MOSFET in briefly explain. (b) Distortion in amplifier circuits. 9). Write short notes on two of the following:- (a) Thermal runway (d) PIN Diodes (c) Effect of –ve feed back on output resistance of an amplifier. Electronic Devices & Circuits (EC-201, DEC-2005) Note: Section A is compulsory. Attempt any four questions from Section B and any two questions from Section C. Section-A 1. (a) What is the main important difference between the characteristics of a simple switch and those of an ideal diode? (b) Compare JFET and MOSFET. Mention at least four points. (c) What is reverse Recovery Time? (d) A dc voltage supply provides 60V when output is unloaded. When connected to a load the output drops to 56V. Calculate the values of voltage regulation. (e) What is “Dark current” of a photodiode? (f) What is negative resistance region? (g) Which two methods makes the collector current constant. Explain them. (h) What is foldback limiting? (i) Calculate dc voltage across 1 Kr load for a RC filter (R=120r, C=10m F). The dc voltage across the initial filter capacitor is 60V. (j) Draw the piecewise linear equivalent circuit of diode and explain it briefly. Section-B 2. Explain the working of CMOS Invertor. Also mention the applications and advantages over other approaches. 3. (a) Describe the differences between re and hybrid equivalent for a BJT transistor. (b) For each model, list the conditions under which it should be applied. 4. A full wave bridge rectifier with 120V rms sinusoidal input has a load resistor of 1k_. (i) If silicon diodes are employed, what is dc voltage available at load? (ii) Determine required PIV rating of each diode. (iii) Find maximum current through each diode during condition. (iv) What is required power rating of each diode? 5. A silicon transistor with _ = 100 is to be used in self biasing circuit shown in figure below, such that the Q-point corresponds to VCE = 12V and IC = 2m A. Find RE if VCC = 24V and RC = 5K_. Fig. 6. (a) What is Miller Theorem? (b) Explain analysis of emitter follower by using this theorem. Section-C 7. (a) What is the significant difference between the construction of an enhancement-type MOSFET and a depletion type MOSFET? (b) Sketch the circuit of a CS amplifier. Derive the expression for the voltage gain at low frequencies. 8. (a) For a zener diode network shown in below fig. Determine VL , VR, IZ and PZ. (b) What do you mean by hot carrier diode? Compare the characteristics of hot carrier and p-n junction diode? Fig. 9. (a) Design a self-bias network using a JFET transistor with IDSS = 8m A and VP = -6V to have a Qpoin at IDQ = 4m A using a supply of 14V. Assume the RD = 3RS and use standard values. (b) Discuss the three configurations of FET biasing. Explain any one in detail. Contact Details: Punjab Technical University Near Pushpa Gujral Science City, Jalandhar- Kapurthala Hwy, Rasulpur, Punjab 144601 0182 266 2521 India [MAP]Map Location: Last edited by Aakashd; July 1st, 2019 at 10:44 AM. |