KARNATAKA STATE OPEN UNIVERSITY

I Semester M. Sc. Degree Examination

PHYSICS: Solid State Physics and Electronic Devices

Time: 3 Hours Max. Marks: 80

Answer all questions

1. a) State and prove Bloch theorem.

b) Distinguish between first and second Brillouin zones. (10+5)

OR

2. a) Using Kronig-Penny model, show that energy spectrum of solids consists of number

of allowed energy bands separated by forbidden gaps.

b) Discuss a method of determining Fermi surface of a metal experimentally. (10+5)

3. a) Discuss the Sommerfeld theory of free electrons

b) Write a note on Umklapp scattering. (10+5)

OR

4. a) Discuss electrical conductivity of metals at high frequency and obtain an expression

for dielectric constant.

b) What is Gudden-Pohl effect? Discuss. (10+5)

5. a) Obtain an expression for carrier concentration in an intrinsic semiconductor

b) Explain the effect of doping on Fermi level in semiconductors. (10+5)

OR

6. a) Mention different mechanisms of excitation and emission processes. Derive an

expression for intensity of temperature independent luminescence.

b) Write a brief note on Destriau effect with an example. (10+5)

7. a) Discuss the formation of space charge region in a p-n junction diode and obtain an

expression for the width of the region.

b) Find the value of applied voltage at 296 K for a p-n junction diode if I0= 35 Î¼A/cm2

and IF=2.6 A/cm2

(10+5)

OR

8. a) With a neat diagram, discuss the construction and working of a JFET.

b) Explain the working of relaxation oscillator using UJT (10+5)

9. Answer any FOUR questions. (5 X 4 = 20)

a) Show that the reciprocal lattice of a b.c.c is f.c.c.

b) Discuss the importance of Fermi surfaces.

c) A photon of energy equal to double the rest mass energy of electron gets back scattered

by an electron. Calculate the wavelength of scattered photon.

d) Write a note on Hall Effect and its importance.

e) In an intrinsic semiconductor at temperature of 298 K the mobility of electrons and

holes are ……… respectively. Calculate its energy gap.

Given: the resistivity of the specimen =0.37Î©m.

f) Write a note on Schotky effect.

g) Obtain an expression for current, when a p-n junction is forward biased.

h) Distinguish between BJT and JFET

I Semester M. Sc. Degree Examination

PHYSICS: Solid State Physics and Electronic Devices

Time: 3 Hours Max. Marks: 80

Answer all questions

1. a) State and prove Bloch theorem.

b) Distinguish between first and second Brillouin zones. (10+5)

OR

2. a) Using Kronig-Penny model, show that energy spectrum of solids consists of number

of allowed energy bands separated by forbidden gaps.

b) Discuss a method of determining Fermi surface of a metal experimentally. (10+5)

3. a) Discuss the Sommerfeld theory of free electrons

b) Write a note on Umklapp scattering. (10+5)

OR

4. a) Discuss electrical conductivity of metals at high frequency and obtain an expression

for dielectric constant.

b) What is Gudden-Pohl effect? Discuss. (10+5)

5. a) Obtain an expression for carrier concentration in an intrinsic semiconductor

b) Explain the effect of doping on Fermi level in semiconductors. (10+5)

OR

6. a) Mention different mechanisms of excitation and emission processes. Derive an

expression for intensity of temperature independent luminescence.

b) Write a brief note on Destriau effect with an example. (10+5)

7. a) Discuss the formation of space charge region in a p-n junction diode and obtain an

expression for the width of the region.

b) Find the value of applied voltage at 296 K for a p-n junction diode if I0= 35 Î¼A/cm2

and IF=2.6 A/cm2

(10+5)

OR

8. a) With a neat diagram, discuss the construction and working of a JFET.

b) Explain the working of relaxation oscillator using UJT (10+5)

9. Answer any FOUR questions. (5 X 4 = 20)

a) Show that the reciprocal lattice of a b.c.c is f.c.c.

b) Discuss the importance of Fermi surfaces.

c) A photon of energy equal to double the rest mass energy of electron gets back scattered

by an electron. Calculate the wavelength of scattered photon.

d) Write a note on Hall Effect and its importance.

e) In an intrinsic semiconductor at temperature of 298 K the mobility of electrons and

holes are ……… respectively. Calculate its energy gap.

Given: the resistivity of the specimen =0.37Î©m.

f) Write a note on Schotky effect.

g) Obtain an expression for current, when a p-n junction is forward biased.

h) Distinguish between BJT and JFET

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