M.Sc. (Semester (CBCS) Examination Nov/Dec-2018
Nano-Technology
FUNDAMENTALS OF NANOTECHNOLOGY IN PHYSICS
Time: 2½ Hours Max. Marks: 70
Instructions: All questions are compulsory.
Figures to the right indicate full marks.
Draw neat diagrams.
Q.1 Choose the correct alternative and rewrite the answer: 14
The diameter of an atom is approximately
2-3 A0 1-3 A0
4-3 A0 3-4 A0
An ionic solid consists of atoms held together by
chemical bonds ionic bonds
molecular solids none of these
Semiconductor quantum dots (SQDs) have properties.
electronic and optical chemical
magnetic all of these
Most properties of atoms are based on the number and arrangement of their

Electrons chemical
magnetic physical
Covalent bonding which forms
molecular solids ionic solids
bonding with free electrons covalent solids
Unit cell can be considered as the building block of a
polymers amorphous material
crystal liquids
A quantum dot is a nanostructure or tiny particle of semiconducting substance
with a diameter range of
20nm to 50nm 30nm to 40nm
20nm to 30 nm 1nm to 10nm
The diameter of the QD is from highest occupied molecular orbital.
increases constant
decreases increases decreases
The bigger quantum dot which gives
higher wavelength lower wavelength
equal wavelength very small wavelength
10) An important parameter in the band theory is the
Fermi level Quantum theory
Mechanical Covalent bonding
11) In a semiconductor p-type is semiconductor.
rejecter donor
equilibrium acceptor
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12) In Polar dielectric materials, when the is applied all dipoles tend
to align in the field direction.
positive electric field internal electric field
external electric field negative electric field
13) Dielectric constant with frequency.
unequal equal
increases deceases
14) The dimensions of nano-crystalline materials of the grains are in the
nonometer range micrometer range
mega meter range millimeter range
Q.2 Answer the following. (Any four)
Define Atomic structure.
What do you mean by covalent solids?
Define Dielectric constant.
What is meant by dipole moment?
Define optical memory.
08
Write notes on. (Any Two)
Atomic structure
Unit cell
Quantum Dots
06
Q.3 Answer the following. (Any Two)
Explain diffraction of X-rays by crystal.
Give a brief explanation on LASER.
Explain Dielectric constant.
14
Answer the following. (Any one)
With a neat diagram explain atomic bonding in Solids.
Give a brief explanation on semiconductor quantum dots.
Q.4 Answer the following. (Any Two)
Describe with a neat diagram electronic polarization.
Explain Lorentz field in cubic material.
Explain applications of electro luminescence.
10
Answer the following. (Any one)
Describe optical properties of Nanomaterials.
Explain properties of micro and Nanomaterials.
04
Q.5 Answer the following. (Any two) 14
Describe with the help of neat diagram intrinsic and extrinsic semiconductor.
With a net diagram explain band model of semiconductor.
Describe with the help of a neat diagram internal or local fields in solid and
liquids.