EC1211 ELECTRONIC DEVICES Nov/Dec 2006. question papers Anna university question papers Download

B.E/B.Tech DEGREE EXAMINATION, Nov/Dec 2006.
Third Semester
Electrical and Electronics Engineering
EC 1211 - ELECTRONIC DEVICES
(Regulation 2004)
Time: 3 hours                                                    Maximum marks: 100
Answer ALL questions
PART A (10 x 2 =20 marks)

1.What are called P and N type semiconductors?
2. What is meant by diffusion current?
3.Define Barrier potential at the junction
4.Draw the hybrid model of CB configuration
5.What is known as pinch off voltage in FET?
6.Draw the symbol and equivalent circuit of UJT.
7. Mention the applications of photoconductive cell
8. Discuss tjhe principle of solar cell
9. Compare SCR and TRIAC
10.What is meant by dark current and dark resistance in phtodiodes?

PART B (5 x 16 = 80)

11 (a)  (i) Derive the expresson for diffuson capacitance in PN junction diodes(6)
(ii)Explain the V-I characteristics of PN junction diode(6)
(or)
(b) (i) Explain the various diode switching times(8).

(ii)Discuss the temperatre effect of PN junction diodes?(8).

12.  (a) (i)Using hybrid model ,obtain the expressions for input and output impedances, voltage and current gain in CE configuration(6)
(ii) Write a note on power transistors
(or)
(b) (i) Dscribe the various current components in a transistor

(ii) Explain the three regions of output characteristics of a transistor in CE configuration

13 (a)(i) Describe the constructon and working principle
(ii) Explain the V-I characteristics of uni junction transistor
(or)
(b)(i) With the constructional details, explain te characteristics of enhancement type MOSFET.

(ii) Distinguish between JFET and MOSFET.

14.  (a) (i) Describe the characteristics of photo transistor with its constructional details.
(ii) Write about laser diode and its applications
(or)
(b) (i) Illustrative photo conductive cell

(ii) Explain the principle of opto couplers. Mention some of ts applications

15.  (a) (i) Explain the V-I characteristics of SCR with consructioal details
(ii) Briefly about zener break down
(or)
b)(i)Explain about varactor dide

(ii)Explain V-I characteristics of tunnel diode.

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