Download AKTU B-Tech 2nd Sem 2015-16 201EAS Engineering Physics Ii Question Paper

Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU)) B-Tech 2nd Semester (Second Semester) 2015-16 201EAS Engineering Physics Ii Question Paper

Printed Pages: 4 NAS-ZOl/EAS-ZOI
(Following Paper ID and Roll N 0. to be ?lled in your
Answer Books)
Paper ID : 199220 R011 N0.| I I I I I | | | |
B. TECH.
Theory Examination (Semester?II) 2015-16
ENGINEERING PHYSIC S-II
Time : 3 Hours Max. Marks : 100
Note: This question paper contains 3 sections. Attempt questions
from each section. Take standard values wherever needed.
Section-A
Q1. Attempt all parts. All parts carry equal marks. Write answer of
each part in short. (2X10=20)
(a) What is primitive's cell ?
(b) What is atomic radius of a simple cubic structure with
a cube edge a ?
(c) What is internal ?eld in dielectric ?
(d) What type of magnetic materials is used to make core
of transformers ?
_ (1) P.T.O.
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Q2.
(6)
(f )
(g)
(h)
(i)
G)
What if displacement current ?
If a plane electromagnetic wave in free space has
magnitude of H 1 A/m. What is the magnitude of E ?
Define the position of Fermi level in intrinsic
semiconductor ?
What do you understand by transition temperature ?
What is the value of critical ?eld of a super conductor
at transition temperature ?
What are the types of single walled nanotube ?
Section-B
Attempt any ?ve questions from this section. (5 X 10:50)
(a)
(b)
(C)
(d)
De?ne crystal structure, crystal lattice and Bravais lattice.
Explain lattice planes in crystal. Determine inter?planer
spacing of a lattice plane in a simple cubic lattice With
edge 2 A0 Which cuts the axis in intercepts ratio 324:5.
What do you mean by polarization of substance? Write
different mechanisms of polarization in a dielectric.
Show that susceptibility of diamagnetio material is negative
and independent of temperature.
(2)
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(e)
(f)
(g)
(h)
Using Maxwell's equations, derive electromagnetic
wave equations in vacuum and prove that wave
propagate with speed of light.
What is Poynting vector? A 500 watt lamp radiates
power uniformly in all directions. Calculate the electric
and magnetic ?eld intensities at l m distance from the
lamp.
How the temperature affects the critical ?eld of a
superconductor? The critical ?elds for lead are 1.8 X
106 A/m at 6 K and 2.4 X 106 A/m at 0 K. Find the
critical temperature of the material.
What are carbon nanotubes? Discuss its properties and
applications.
Section-C
Note :Attempt any two questions from this section. (2X15=30)
Q3. Explain the Braggs law. Describe Bragg?s spectrometer and
explain with example how it is used to study the crystal
structure?
Q4- (21)
(b)
What is dielectric constant? Derive Clausius Mossotti
equation for non polar solids having cubic structure.
Explain the behavior of dielectric in an alternating electric
?eld. What is relaxation time?
(3) P.T.O.
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5. (3) De?ne drift velocity, mobility and conductivity of a
semiconductor. Obtain an expression for the electrical
conductivity of an intrinsic semiconductor.
(b) Determine the number density of a donar atoms Which
has to be added to an intrinsic gennanium semiconductor
to produce a n-type semiconductor of conductivity
5 ohm?1 cm?l, given that the mobility of electron in n-
type germanium is 3900 cmZ/(V - s). Neglect the
contribution of holes to conductivity.
(4)
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