GITAM University 2008 B.E Electronics %26amp%3B Tele-Communication Engineering Analog Electronic Circuits - Question Paper

PART – A
1. ans the subsequent. 10x2=20

a) What is the merit and demerit of RC coupled amplifiers?

b) How is the bandwidth related to the rise time of a BJT?

c) Prove that the noise gets decreased approximately by a factor of kA, when negative feedback is introduced (k is feedback factor and A is open loop gain).

d) Draw a circuit diagram which introduces current series feedback.

e) What is the drawback of Colpitts oscillator and how is it taken care of?

f) Draw the equivalent circuit of a crystal.

g) What is the cause for lowest efficiency in resistive loaded class A power amplifiers?

h) What is thermal runaway?

i) Draw a double tuned amplifier circuit using FET.

j) Draw the equivalent circuit of single tuned amplifier.

PART – B

ans any 4 of the subsequent. If you attempt more than 4 questions, only the 1st 4 in order will be valued.

2.
a) What is the effect of multistage on gain and bandwidth? discuss with the help of derivations.

b) Derive the expression for voltage gain of a common collector amplifier in terms of h parameters.

3.
a) Draw the small signal circuit of a common emitter amplifier with the effect of coupling capacitor taken into account and comment.

b) Prove that the bandwidth of a negative feedback widens to the extent its voltage gain gets decreased.
4.
a) Draw the practical circuit diagram of a negative feedback amplifier whose input impedance gets enhanced and output impedance decreased due to feedback. Justify.

b) How do you compute the amount of feedback provided in a negative feedback amplifier? Illustrate.

5.
a) Draw a Colpitts oscillator using BJT and derive the expression for the frequency of oscillation.

b) Write a note on amplitude stability of oscillators.
6.
a) Draw a transformer coupled class B amplifier and discuss its operation. elaborate its drawbacks?

b) Mention 3 salient points about complementary symmetry power amplifiers.
7.
a) Why is the efficiency of class C power amplifiers the highest? Support your ans with derivation.

b) Write a short note on heat sinks.
8. Write note on
a) Stagger tuned amplifier.
b) Frequency stability of oscillator.

Earning:   Approval pending.