RGPV Exams Questions Papers – 3rd SEM. – June- 2008, Electronics

B.E. (Third semester) EXAMINATION, JUNE. 2008

(Common for EC/EE/EX Engg.)

(ELECTRONIOCS)

(CS/EE/IP-304)

 

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

1. (a)  What is a varactor diode ? Write its application.

(b)  How does the diode voltage vary with temperature ?

(c )  Explain with the help of diagram the working of N-channel FET and draw its volt-ampere

        characteristics .

2. (a) Draw the complete output and input characteristics of CE amplifier and explain them.

    (b)  A transistor used in CE connection has the following set of h-parameters.

         Hie = 1k, hfe=  100, hre = 5 × 10-4 ,and hoe 2 × 10-5  with RL = 5 K,

         Determine Ri and Ai.

3. (a) What is feedback amplifier ? Discuss the advantages and disadvantages of negative feedback.

    (b)  Prove how input resistance is increased in volyage-series feedback topology ?

4. (a) Write the difference between an enhancement and depletion type MOSFET.

    (b)  Determine the quiescent and the collector to emitter voltage for a silicon transistor with ß=50 I       

           the  self – biasing arrangement of  fig.

 

 

 

5. (a) What do you mean by class-A , class –B and class-C amplifiers?

    (b) Discuss the merits of push pull power amplifier over single ended power amplifier .

    (c ) Define CMRR for an operational amplifier .

6. (a)  What is a multavibrator circuit ? Draw the circuit diagram of biastable multavibrator and explain

            its working .

(b)  What do you mean by clamping circuits ? Explain.

7. (a) Draw the circuit diagram of a Wien’s bridge oscillator and explain its operation .

(b) What is an operational amplifier ? How it works as a

      (i) Differentiator ?

      (ii)  Comparator ?

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

      (i)  Thermal stability

    (ii)    Clipping circuits

    (iii)   Tunnel diode

   (iv)    IC-555

   (v)    Effect of feedback on output resistance 

   (vi)  Boot strapping technique.

 

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