SRM University 2007 B.Tech Electronics and Communications Engineering EC202- ELECTRONIC CIRCUITS – II - Question Paper

8. A phase shift oscillator is to use a feedback network consisting of four RC parts. Derive an approximate expression for the frequency of oscillation.

9. (a) What disadvantages does a phase shift oscillator have?
(b) How is this overcome in a Wein-Bridge oscillator?
(c) What function does the Wein-bridge part have in Wein-Bridge oscillator?
(d) Why is the bridge not used to give phase shift?

10. Sketch the circuit diagram for a Wein-Bridge oscillator that uses a 2 stage BJT amplifier. discuss the circuit construction and operation. find an expression for frequency of oscillation.

11. Describe a Piezo-Electric crystal as used with electronic circuits. Sketch the crystal equivalent circuit and impedance / frequency graph. discuss the behavior of electronic crystals.

12. Draw the circuit diagrams of (a) a series operated crystal oscillator and (b) a shunt-excited crystal oscillator. discuss the construction and operation of the circuit.

UNIT – III - LARGE SIGNAL AMPLIFIERS
Part - A
1. What is power amplification? describe a power amplifier.
2. What is the need of power amplifier in audio applications?
3. What are the differences ranging from a voltage amplifier and power amplifier? Distinguish ranging from them.
4. Which amplifiers are classified as power amplifiers? discuss the general features of a power amplifier.
5. Explain why a voltage amplifier cannot be efficiently used as a power amplifier, though useful power is developed at the output of voltage amplifier?
6. What are the performance volumes of a power amplifier? discuss them.
7. How do you classify power amplifiers?
8. What is Class-A operation?
9. Explain the Q-point placement in Class-A power amplifier with neat sketches of loadline.
10. What are the merits and demerits of class-A power amplifier?
11. Mention a few of the important applications of Class-A amplifier.
12. What is Class-B operation?
13. Explain the Q-point placement in Class-B power amplifier with neat sketches of loadline.
14. What are the merits and demerits of class-B power amplifier?
15. Mention a few of the important applications of Class-B amplifier.
16. What is Class-C operation?
17. Explain the Q-point placement in Class-C power amplifier with neat sketches of loadline.
18. What are the merits and demerits of class-C power amplifier?
19. Mention a few of the important applications of Class-C amplifier.

Earning:   Approval pending.