B.E./B.Tech. DEGREE EXAMINATION, NOVEMBER/DECEMBER 2011.
B.E. — Electrical and Electronics Engineering
131303 — ELECTRONIC DEVICES AND CIRCUITS
Time : Three hours Maximum : 100 marks
Answer ALL questions.
PART A — (10 ´ 2 = 20 marks)1. Define Drift current.
2. Define zener breakdown voltage.
3. Draw the configuration of CB,CE &CC.
4. What are Optocouplers?
5. Compare FET and JFET.
6. Sketch the Darlington pair of CE.
7. What are feedback amplifiers.
8. List any two applications of the differential amplifier.
9. Sketch the clamper circuit.
10. Categorize the types of Multivibrators.
PART B — (5 ´ 16 = 80 marks)11. (a) (i) Explain the V-I Characteristics of PN junction diode. (8)
(ii) Explain the principle of operation of a Full wave rectifier. (8)
(b) (i) Explain how Zener diode acts as a Voltage Regulator. (12)
(ii) Compare LCD and LED. (4)
12. (a) Sketch neatly the circuit diagram of a CE configuration transistor,
discuss its operation, characteristics and compare it with the other modes
of operation. (16)
(b) (i) Derive the Hybrid model for a CE Amplifier. (12)
(ii) What are Power transistors? (4)
13. (a) Discuss in detail about the Working and operation of JFET and explain
about the I/O Characteristics. (16)
(b) (i) Explain the operation and Characteristics of an Enhancement mode MOSFET. (8)
(ii) Explain the operation and Characteristics of a Depletion mode MOSFET. (8)
14. (a) Explain the working of differential amplifier in both common and
differential mode. (16)
(b) (i) Explain the operation of voltage (series/shunt) feed back amplifier.(12)
(ii) List the different types of oscillators and briefly explain any one
type of oscillator. (4)
15. (a) Explain the working and operation of a Monostable Multivibrator with a
neat circuit diagram. (16)
(b) (i) Explain the operation of a Schmitt trigger with neat diagram. (8)
(ii) Explain the operation of UJT saw tooth oscillator with suitable