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

Monday, 21 January 2013 12:05Web

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. |