Download VTU ((Visvesvaraya Technological University) B.E/B-Tech 2019 July ( Bachelor of Engineering) First & Second Semester (1st Semester & 2nd Semester) 17 Scheme 17PHY12 Engineering Physics Question Paper
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ro
cHworYI
USN
First/Second Semester B.E. Degree Examination, June/July 2019
Engineering Physics
Time: 3 hrs.
Max. Marks: 100
Note: 1. Answer any FIVE full questions, choosing one full question from each module.
2. Physical Constants : Velocity of light, c = 3 x 10
8
ins"'
Mass of electron, tn, = 9.1 x 10
-31
4
Boltzmann constant, Kg
=
1.38 x 10
-23
.1/k
Charge of an electron, e = 1.6 x 10
49
C
Avagadro number, NA = 6.02 x 10
26
/k mole
Module-1
1 a. What is ultraviolet catastrophe? Discuss in brief Wien's law and Rayleigh-Jeans law to
0c
explain blackbody radiation_
(06 Marks)
,
1)
+
?-
b. Solve the Schrodinger's wave equation for the allowed energy values in the case of particle
in a box and also find eigen function for the same and represent with figure. (10 Marks)
;- ?-)
c. Calculate the wavelength associated with an electron having a kinetic energy of 100 eV.
O
(04 Marks)
?
.
0
OR
2 a. Define group velocity and phase velocity. Derive the relation between the two. (06 Marks)
ct
b. Mention the properties of the wave function. Set up time-independent one-dimensional
? -a
to a.
Schrodinger's equation. (10 Marks)
8
c. In a measurement that involved a maximum uncertainty of 0.003%, the speed of an electron
?
z was found to be 800 ms
-
'. Calculate the corresponding uncertainty involved in determining
i
?
; its position. (04 Marks)
7 s
v
c
?
Module-2
'
1
3 a. Define the following terms: (i) Drift velocity (ii) Relaxation time. Discuss the drawbacks
of classical free electron theory in metals. (08 Marks)
3
b. Define critical magnetic field. Explain types of super conductors. Mention applications of
m 4,---
super conductors. (08 Marks)
,...
cu
o
, ,,-
?
c. The effective mass of an electron in Silicon (Si) is 0.31 m
0
, where m
0
is free electron mass.
?
?
-0
,..
)
t-- 0
Find the electron concentration for Si at 300 K, assuming that Fermi level lies exactly in the
? ..._ -
v) := middle of energy gap. Given energy gap of Si = 1.1 eV. (04 Marks)
-
a 2
P
u
? .?-.' OR
a .,
4 a. Briefly explain Fermi-Dirac statistics and discuss the dependence of Fermi-factor on
temperature. (06 Marks)
b. State and explain Meissner effect. (05 Marks)
7
c. Explain BCS theory for superconductivity_ (05 Marks)
a.
d. The resistivity of intrinsic Silicon at 27?C is 3000 c2m. Assuming electron and hole
mobilities of 0.17 m
--
V
-
' S
-
' and 0.035 ni
2
V
-I
S
-1
respectively. Calculate intrinsic carrier
concentration. (04 Marks)
I oft
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17PHY12/22
socset
ro
cHworYI
USN
First/Second Semester B.E. Degree Examination, June/July 2019
Engineering Physics
Time: 3 hrs.
Max. Marks: 100
Note: 1. Answer any FIVE full questions, choosing one full question from each module.
2. Physical Constants : Velocity of light, c = 3 x 10
8
ins"'
Mass of electron, tn, = 9.1 x 10
-31
4
Boltzmann constant, Kg
=
1.38 x 10
-23
.1/k
Charge of an electron, e = 1.6 x 10
49
C
Avagadro number, NA = 6.02 x 10
26
/k mole
Module-1
1 a. What is ultraviolet catastrophe? Discuss in brief Wien's law and Rayleigh-Jeans law to
0c
explain blackbody radiation_
(06 Marks)
,
1)
+
?-
b. Solve the Schrodinger's wave equation for the allowed energy values in the case of particle
in a box and also find eigen function for the same and represent with figure. (10 Marks)
;- ?-)
c. Calculate the wavelength associated with an electron having a kinetic energy of 100 eV.
O
(04 Marks)
?
.
0
OR
2 a. Define group velocity and phase velocity. Derive the relation between the two. (06 Marks)
ct
b. Mention the properties of the wave function. Set up time-independent one-dimensional
? -a
to a.
Schrodinger's equation. (10 Marks)
8
c. In a measurement that involved a maximum uncertainty of 0.003%, the speed of an electron
?
z was found to be 800 ms
-
'. Calculate the corresponding uncertainty involved in determining
i
?
; its position. (04 Marks)
7 s
v
c
?
Module-2
'
1
3 a. Define the following terms: (i) Drift velocity (ii) Relaxation time. Discuss the drawbacks
of classical free electron theory in metals. (08 Marks)
3
b. Define critical magnetic field. Explain types of super conductors. Mention applications of
m 4,---
super conductors. (08 Marks)
,...
cu
o
, ,,-
?
c. The effective mass of an electron in Silicon (Si) is 0.31 m
0
, where m
0
is free electron mass.
?
?
-0
,..
)
t-- 0
Find the electron concentration for Si at 300 K, assuming that Fermi level lies exactly in the
? ..._ -
v) := middle of energy gap. Given energy gap of Si = 1.1 eV. (04 Marks)
-
a 2
P
u
? .?-.' OR
a .,
4 a. Briefly explain Fermi-Dirac statistics and discuss the dependence of Fermi-factor on
temperature. (06 Marks)
b. State and explain Meissner effect. (05 Marks)
7
c. Explain BCS theory for superconductivity_ (05 Marks)
a.
d. The resistivity of intrinsic Silicon at 27?C is 3000 c2m. Assuming electron and hole
mobilities of 0.17 m
--
V
-
' S
-
' and 0.035 ni
2
V
-I
S
-1
respectively. Calculate intrinsic carrier
concentration. (04 Marks)
I oft
17PHY 2/22
Module-3
5 a. Explain construction and working of semiconductor laser with the help of energy band
diagram. (07 Marks)
b. Describe recording and reconstruction process in holography with the help of suitable
diagram. Mention its applications. (09 Marks)
c. A medium in thermal equilibrium at temperature 300K has two energy levels with a
wavelength separation of 1 p_tm. Find the ratio of population densities of the upper and lower
levels. (04 Marks)
OR
6 a. Obtain an expression for energy density of radiation under equilibrium condition in term of
Einstein's coefficients. (06 Marks)
b. Discuss types of optical fibers using suitable diagrams. (06 Marks)
c. Explain point to point communication system using optical fiber with block diagram.
(04 Marks)
d.
The attenuation of light in an optical fibre is estimated as 2.2 dB/km. What fractional initial
intensity remains after 2 km and 6 km? (04 Marks)
Module-4
7 a. What are Miller Indices? Show that for cubic the distance between two successive plane
,() is given by d = a (07 Marks)
VW
.
+ 1(
2
+P
b. Define coordination number, atomic radius and atomic packing factor. Find atomic packing
factor for SC, BCC and FCC. (09 Marks)
c. X-rays of wavelength 1.541 A are diffracted by (1 1 1) planes in a crystal at an angle of 30?
in the first order. Calculate the inter atomic spacing. (04 Marks)
OR
8 a. Explain the procedure followed to specify
example.
b. State and explain Bragg's law. Describe how
wavelength of an x-ray beam.
e. Draw following planes in cubic unit cell (100
crystal planes using Miller indices with an
(05 Marks)
Bragg's spectrometer is used to determine the
(10 Marks)
) (110) (011) (111) (001). (05 Marks)
Module-5
9 a. Explain the construction and working of scanning electron
applications.
b. Explain Ball-Milling method of synthesis of nanomatcria Is.
c. Write any four applications of carbon nano tube.
microscope. Mention its
(10 Marks)
(06 Marks)
(04 Marks)
10 a.
b.
e.
OR
Explain top-down and bottom-up approach in synthesis of nano-materials.
Explain the construction and working of Reddy's shock tube.
Describe the various quantum structures.
society.,
CHIKODI
LIBRARY
(06 Marks)
(06 Marks)
(08 Marks)
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,
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This post was last modified on 01 January 2020