GITAM University 2008 B.E Electronics & Tele-Communication Engineering Electronics and Communication Analog Electronic Circuits - Question Paper

GITAM University B.E Electronics and Communication Analog Electronic Circuits ques. paper

Gandhi Institute of Technology and Management, Visakhapatnam
(Affiliated to Andhra University)

B.E. (Electronics and Communications Engineering) 2nd Year
Second Semester exams 2004-2005
(Autonomous Stream)

EC 222 Analog Electronic Circuits

Time: three Hours Max. Marks: 60

1. ans ques. No. one ( Part – A) and any 4 of the remaining 7 (Part – B)
2. All parts of a ques. must be answered in 1 place, otherwise they will not be valued.
3. Figures in the right hand margin indicate marks allotted.

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.