EE2203 ELECTRONIC DEVICES AND CIRCUITS -ANNA UNIVERSITY PREVIOUS YEAR QUESTION PAPER NOV/DEC 2010 For EEE DPT (3rd Sem) ...
Posted by R.Anirudhan
B.E./B.Tech. DEGREE EXAMINATION, NOVEMBER/DECEMBER 2009
Electrical and Electronics Engineering
EE 2203 — ELECTRONIC DEVICES AND CIRCUITS
Time : Three hours Maximum : 100 Marks
Answer ALL Questions
PART A — (10 × 2 = 20 Marks)1. What is diffusion current in PN Junction diode?
2. What is LED? Which material is used for LED?
3. Why is collector region wider than emitter region in BJT?
4. In a BJT, the emitter current is 12 mA and the emitter current is 1.02 times
the collector current. Find the base current.
5. What are the special features of FET?
6. Define :
(a) Pinch off voltage and
(b) Amplification factor in JFET.
7. What is meant by Common mode Rejection Ratio?
8. Give the Barkhausen’s criterion for oscillators.
9. Mention some applications of UJT.
10. What is a multivibrator?
PART B — (5 × 16 = 80 Marks)11. (a) (i) Draw and Explain the VI characteristics of a PN Junction diode. (6)
(ii) Explain the operation of a Full wave Rectifier and derive its Ripple
(b) (i) Explain the working of a Zener diode as a Regulator. (8)
(ii) Discuss the working principle, characteristics and applications of
LED in detail. (8)
12. (a) (i) Draw and explain the Input and Output characteristics of a BJT in
CE configuration. (12)
(ii) Write a note on optocouplers. (4)
(b) (i) Draw the Hybrid model of CE configuration and also derive the
expressions for its Input and Output Impedances, current and
voltage gain. (12)
(ii) Explain the switching characteristics of a transistor. (4)
13. (a) Explain in detail the construction and working principle of Depletion
MOSFET. Also explain how Depletion MOSFET acts both in
enhancement and depletion mode.
(b) (i) With a neat circuit diagram explain the operation of a common
source amplifier. (6)
(ii) From the low frequency model, determine the input and output
impedances and the voltage gain of a JFET. (10)
14. (a) (i) Discuss the various topologies of feed back amplifier. (8)
(ii) Discuss the operation of a colpitts oscillator in detail. (8)
(b) (i) Explain the effects of negative feedback in amplifiers. (8)
(ii) Describe the operation of a typical voltage shunt feedback amplifier.
15. (a) (i) What is a clipper and clamper? Explain the concept of a positive
clipper and a clamper. (12)
(ii) Distinguish between Astable and Bistable multivibrators. Mention
some applications. (4)
(b) (i) What is a Schmitt Trigger? Discuss any two applications of Schmitt
(ii) Explain the application of UJT as a Sawtooth oscillator. (8)