RGPV Exams Questions Papers – 3rd SEM. – Dec- 2004, Electronics

B.E. (Third semester) EXAMINATION, DEC, 2004

(Common for EC/EE/IP Engg.)





Note:      Attempt any five questions.  All question carry equal marks. Assume any data  missing.

1. (a) Explain the V-1 characteristics of zener diode and explain its working as a voltage regulator .

     (b)  Define the pinch off voltage V p. Sketch the depletion region before and after pinch off. How does

           FET behaves in the region  before and after pinch off ?

2. (a) Distinguish between positive feedback and negative feedback . List the characteristics of an

           amplifier that get modified by negative feedback.

    (b)  Explain the Wien’s  bridge oscillator using BJT. For this circuit calculate the frequency of      


3. (a) Draw a self bias circuit for a transistor . Why these circuit has an improvement on fixed bias circuit

         ? How the load line is drawn in self bias circuit.

 (b)    Determine the d.c. bias voltage V CE   And the current IC From the circuit given below :





4. (a) Give the characteristics of class- A power amplifier . Deduce the expressions where necessary.

    (b)   A transformer coupled class – A amplifier , maximum collector current charge is 100 mA ; VCC =10 .

           Find the power transferred to 4 ohm speaker load if it is

          (i) Direct coupled (ii) Transformer coupled (Find the turn ratio of transformer)

5. (a) Draw the circuit of Bitable multavibrator . Explain its working.

  (b)  What is voltage comparator ? How to generate a saw-tooth using op-amps ?

6. (a) Explain the operation of a transistorized differential amplifier . Show the input bias currents clearly

          and how input offset current can be minimized ?

(b)  What are the characteristics of an ideal Op-Amp . Derive the formulas for inverting and non-verging 


7. (a) Explain V-1 characteristics of SCR . What is meant by Gate on and Off times ?

   (b)  Explain the operation and application  of convertor . invertors and choppers circuits.

8.     Write short notes on any three of the following  :

(a) Varactor diode

(b) h-parameter

© Hartley oscillator

(d) Instrument  amplifier

(e) Power MOSFET and IGBT


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