B.E. (Third semester) EXAMINATION, Dec. 2007
(Common for EC/EE/EX Engg.)
Note: Attempt any five questions in all. Attempt one question from each unit. Assume suitable data
missing data if any.
1. (a) Give V-1 characteristics of P-N diode and explain the same with forward and reserve biasing of
(b) What is Zender diode? How is it different from the a P-N junction diode ? Explain with different
breakdown mechanism of BJT.
2. (a) What are the different operating regions of a BJT ? Explain .Also give amplification of BJT.
(b) Explain the following:
(i) Biasing of BJT (ii) Q-point
(iii) (iv) D.C. load line
3. (a) Discuss biasing techniques for BJT in brief.
(b) An amplifier is shown in fig.1. Calculate the output voltage for input voltage of 1mV (r.m.s.)
assuming that B=80 and Rin =2K .
4. (a) Define h-parameters for BJT . Determine voltage and current gain in terms of h-parameters for BJT
at low frequency .
(b) Calculate the current and voltage gain of a CE amplifier having the following g parameters.:
Hie = 1100 ohm, hre =2.5 × 10-4 , hfe = 50,
Hoe = 25 × 10-6 mho, Rs = 1k-ohm, RL = 1 k ohm.
5. (a) What re the four feedback configuration ? Explain and define feedback factor.
(b) Draw the circuit diagram of an emitter follower and discuss about the feedback mechanism
6. (a) Give the classification of power amplifiers .
(b) What is Wien bridge oscillator ? Explain and derive expression for frequency of oscillator.
7. (a) Analysis the switching action of BJT.
(b) What is astable multavibrator ? Explain
8. (a) What is differential amplifier ? Explain and define its basic parameters of analysis.
(b) What is boot strapping ? Explain
9. (a) Give the characteristics of an ideal OP-AMP and explain.
(b) What is summing OP-AMP amplifier? Give its analysis.
10. (a) Determine the voltage gain of an OP-AMP instrumentation amplifier .
(b) What is Schmitt trigger ? Explain