Anna University Chennai 2005 B.E Electronic Instrumentation & Control Engineer /B.TECH :Electron Devices - Question Paper

B.E/B.TECH. DEGREE exam ,APRIL/MAY 2005
Third semester ,Instrumentation and control engineering
Electron Devices

Time: 3Hrs
Maximum:100 marks

PART A (10 X two =20)

1. describe electrostatic deflection.

2.List the applications of CRO

3.Define depletion layer capacitance in a PN junction.

4.Determine the germanium PN junction diode current for the forward bias voltage of 0.22 V at room temperature 25 degree C ,with reverse saturation current equal to one mA.

5. describe leakage current in a transistor in common emitter configuration.

6. describe transistor insaturation.

7.What is the effect of gate to source voltage on drain charecteristics in a FET?

8.Draw the equivalent circuit of a UJT.

9.List the unique features of LED.

10.Draw the VI charecteristics of a photo diode.

PART B ( five X16 =80)

11.Derive from 1st principle the parameters input/output/feedback conductance ,base spreading resistance and transconductance for the high frequency hybrid - pie model of a transistor.

12 (a) Derive the effect of electric and magnetic field on a electron

OR

(b) Draw the block diagram of a CRO and discuss how to measure voltage frequency waveform.

13 (a) (i)How does the generation and recombination of electron -hole pair take place?Explain

(ii) Derive the continuity formula.

OR

(b) Derive the diode formula from 1st principle and show how charecteristics depends on temperature

14 (a) Draw and discuss the structure and charecteristics of JFET and derive the expression for pinch off voltage

OR
(b) Draw and discuss the SCR and its V-I charecteristics

15 (a) discuss the concept and theory of charge coupled devices

OR

(b) Draw and discuss the solar cell,with device details and operation.

Earning:   Approval pending.