RGPV Electronics Exams Questions Papers 3rd SEM Dec 2005

RGPV Exams Questions Papers 3rd SEM Dec 2005 Electronics

RGTU B.E. (Third semester) EXAMINATION, DEC, 2005

(Common for EC/EE/IP Engg.)



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

1. (a) (i)  For the given network shown in figure 1, determine the range of RL  AND IL  that will result in

VRL  being maintained at 10 V.

(ii)  Determine the maximum wattage rating of diode.



(b)  Compare the characteristics of Si and Get diode and determine which would you prefer for most

practical application.

2. (a) Find the transistor currents in the circuits of figure shown below. A silicon transistor with ? =100

and ICO = 20 nA.

(ii)  Repeat part (i) if a 2 k   emitter resistor is added to the circuit in figure.





(b)  Explain the early effect in BJT with the aid of necessary plots.

3. (a) State and explain the barkhausen criterion for oscillations.

(b) Describe the operations of Wien bridge oscillator using an op-amp . Derive the expression for

frequency of oscillations.

4. (a)  The circuit  of fig. 3 shown ahead has the following parameters.

R=4 K, R’ =40 K, RS = 10 k, hie  =1.1 k, hfe = 50, hoe =0

Find :

(i) Avf     (ii) Rif    (iii) Rof




(b)  Explain various advantages of negative in amplifiers.

5. (a) Describe the Darlington connection with the help of a circuit diagram. What are the advantages of

it? Explain the biasing in it.

(b)     Diffrencaite between clippers and champers.

6. (a) Define the following :

(i) CMRR  (ii) PSRR  (iii) Slew rate

(iv) Input offset current

(v)  Output offset voltage.

(b)     Draw the circuit of the following using an Op-amp and explain their operation :

7. (a) Draw and explain the characteristics of SCR.

(B)   Describe the solid state firing circuits using UJT.

8. (a) Write short notes on any two of the following :

(i)  Colpitts and Hartley oscillator

(ii)   Astable  multivabrator

(iii)  RC phase shift oscillator

(iv)   Photo – diode





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