Periyar University 2006 B.Sc Electronics PHYSICS OF MATERIALS AND SEMICONDUCTOR DEVICES - Question Paper

First Semester
Electronics
PHYSICS OF MATERIALS AND SEMICONDUCTOR
DEVICES

Time : 3 hours Maximum : 100 marks
part A — (10 x two = 20 marks)
ans ALL ques..
1. Among the crystal structures, which has the
highest packing fraction
(a) BCC (b) FCCandHPP
(c) Diamond cubic (d) Hexagonal.
2. Which bond is available in the 3 states of
matter?
(a) Metallic bond (b) Co-valent bond
(c) Ionic bond (d) Vander Waals bond.

3. The mass of an electron varies with variation in
(a) electrostatic field
(b) magnetic field
(c) gravitational field
(d) speed.
4. Which of the subsequent element has the least
ionization energy?
(a) Al (b) B
(c) pb (d) Sr.
5. At 0°K, a semiconductor acts as
(a) super conductor
(b) good conductor
(c) insulator
(d) same as semiconductor.
6. The gap ranging from the conduction band and valence
band is called as
(a) Conduction gap (b) Forbidden energy gap
(c) Fermi gap (d) Valence band.
2 S.No. 402


7. The avg. a.c. resistance of a PN junction diode
is
(a) AVd/AJd (b) VP/ID
(c) 4L (d) V/I.
dl
8. Which of the subsequent is referred as a double
based diode?
(a) MOSFET (b) FET
(c) SCR (d) UJT.
9. The value of current beneath which SCR is switched
to blocking state is a
(a) Forward current
(b) Knee current
(c) Break over current
(d) Holding current.
10. Which 1 of the subsequent is a most temperature
sensitive device?
(a) SCR (b) UJT
(c) BJT (d) Thermistor.
part B — (5 x six = 30 marks) ans ALL ques..
11. (a) Write a note on metallic bonding.
Or (b) describe the basic crystal systems.
12. (a) discuss Bruillouin zone theory concerned with
electron theory of metals.
Or
(b) Write short notes on :
(i) Electronic work function of a metal (ii) Fermi energy of a metal.
13. (a) discuss the formation of a N-type semi
conductor diagramatically.
Or
(b) List down the applications of Hall effect.
14. (a) discuss the V-I characteristics of a JFET.
Or (b) Write a short notes on :
(i) Static resistance of a PN junction diode (ii) Intrinsic stand off ratio of a UJT.
4 S.No. 402
[P.T.O.]


15. (a) discuss the 2 transistor model of a SCR
with neat sketch.
Or
(b) discuss the operation of a basic Charge Coupled Device (CCD).
part C — (5 x 10 = 50 marks)
ans ALL ques..
16. (a) elaborate Bravais lattices? discuss the
various kinds of Bravais lattices in detail.
Or
(b) List various kinds of bonds occurring in crystals. define the important characteristics of every kind.
17. (a) explain the cause for the failure of classical
free electron theory of metals. discuss the salient
features of quantum free electron model.
Or
(b) explain Mathrissen's rules.
18. (a) Sketch the variation of conductivity with
temperature in the case of intrinsic and extrinsic semi
conductors. What do you infer from them?
Or
(b) discuss Hall effect in detail. How it is used to identify the kind of a semiconductor?
19. (a) discuss the operation of a N-channel JFET
with neat diagram.
Or
(b) discuss the operation of a Tunnel diode based on band.
20. (a) discuss any 3 applications of SCR.
Or
(b) explain about Hall effect Transducers with necessary sketch.

Earning:   Approval pending.