Exam Details
| Subject | atomic, nuclear physics—i and solid-state physics—i | |
| Paper | ||
| Exam / Course | physics | |
| Department | ||
| Organization | Mizoram University | |
| Position | ||
| Exam Date | 2018 | |
| City, State | mizoram, |
Question Paper
PHY/IV/EC/07 Student's Copy
2 0 1 8
CBCS
4th Semester
PHYSICS
FOURTH PAPER
Atomic, Nuclear Physics-I and Solid State Physics—I
Full Marks 75
Time 3 hours
PART A—OBJECTIVE
Marks 25
The figures in the margin indicate full marks for the questions
SECTION—A
Marks 10
Tick the correct answer in the brackets provided 1×10=10
1. If EP and EK are the potential and kinetic energy of an electron in the
stationary orbit in hydrogen atom, the value of EP /EK is
2
1
2. Ka characteristic X-ray refers to the transition from
n 2 to n
n 3 to n 2
n 3 to n
n 4 to n 2
/340 1 Contd.
3. Complete the nuclear reaction 17
35
16
32
2
Cl L® S He4
1
H1
0
n1
1
H2
0
e1
4. If each fission of 92
U235 releases an energy of 200 MeV, how many fissions
must occur per second to produce a power of 32 ´106
3 × 2 ´1018
32 ´1018
1018
1020
5. The coordination number for closed packed crystal structure is
4
8
12
16
6. Miller indices for octahedral plane in cubic crystal is
0
1
1
None of the above
PHY/IV/EC/07/340 2 Contd.
7. X-ray diffraction patterns are used for studying crystal structure of solids
because
they have very high energy, hence they can penetrate through
solids
they are electromagnetic radiation, and hence do not interact with
matter (crystal)
their wavelengths are comparable to interatomic distances
their high frequency enables rapid analysis
8. Which one of the following is not a strong bond?
van der Waals bond
Covalent bond
Metallic bond
Ionic bond
9. The ratio of Fermi energy EF to Fermi temperature TF is equal to
Planck's constant
Boltzmann's constant
Universal gas constant
Rydberg's constant
10. The average kinetic energy of electrons in metals at 0 K is
1
2
mv2
KT
3
5
NeF
3
5
eF
PHY/IV/EC/07/340 3 Contd.
SECTION—B
Marks 15
Answer the following questions 3×5=15
1. State Pauli's exclusion principle, and hence deduce the maximum number
of electrons which can occupy a given shell.
OR
State the advantage and failure of Aston's mass spectrograph.
2. Mention the properties of b and g rays.
OR
In the b-decay, what is the significance of the emission of an antineutrino or
absorption of a neutrino?
3. What are crystal planes? Draw the crystal plane with intercepts
OR
Define lattice parameters. How do you identify a crystal system using lattice
parameters?
4. What are X-rays? What energy of wavelength must they have if they are to
be used in diffraction experiments for the purpose of characterizing crystal
structure?
OR
The Madelung constant of a stable solid is always positive. Why must that
be so?
5. State and explain Wiedemann-Franz law.
OR
Define Fermi velocity.
PHY/IV/EC/07/340 4 Contd.
PART B—DESCRIPTIVE
Marks 50
The figures in the margin indicate full marks for the questions
1. Define Compton effect. Derive an expression for the change in
wavelength when an incident radiation of wavelength l is scattered by a
free electron at an angle q.
Both photoelectric effect and Compton effect arise due to the action of
photons on electrons, but the two effects are not same. Explain this. 3
OR
Give the construction and working of Bainbridge's spectrograph. 7
Mention three interesting uses of mass spectrograph. 3
2. State radioactive decay law, and hence derive the decay equation. Give
the significance of decay constant l.
Show that the density of a nucleus is independent of its mass number. 2
Write a short note on 'Radio Carbon Dating'. 4
OR
What is the source of stellar energy? Explain the carbon-nitrogen cycle
reactions responsible for the stellar energy.
Explain how nuclear fission differs from nuclear fusion. 2
It is estimated that the energy released in the atomic bomb explosion
at Hiroshima was about 7 × 6 ´1013J. If on the average 200 MeV energy
was released on fission of one 92
U235 atom, calculate—
the number of uranium atoms fissioned;
the mass of uranium used for the bomb. 3
PHY/IV/EC/07/340 5 Contd.
3. What is packing factor? Determine the atomic packing factor of FCC
lattice.
Discuss Bravais lattice in three-dimensional crystal. 5
OR
Distinguish between primitive cell, non-primitive cell and conventional
cell. 3
What are Miller indices? How are they determined? Show that in a
cubic crystal the spacing between consecutive parallel planes of Miller
indices is given by
d a
h k l
hkl
2 2 2
4. What do you mean by lattice constant and coordination number? 2
How do you determine the Madelung constant for a NaCl crystal? 3
Derive Laue's equations and hence deduce Bragg's law of X-ray
diffraction. 5
OR
How would you compare van der Waals' bonds, ionic bonds and
covalent bonds? 3
What do you mean by reciprocal lattice vector? Derive the relation
between direct and reciprocal lattice vectors.
Write a brief note on concept of cohesive energy. 2
PHY/IV/EC/07/340 6 Contd.
5. Deduce Dulong and Petit's law for specific heat of solids from the
concept of harmonic oscillator. Discuss the agreement of the result with
that of the experiment.
Discuss Einstein's theory of specific heat of solids. 5
OR
Define Fermi energy and Fermi temperature. How are they related? 3
Using Fermi-Dirac distribution function, explain the effect of
temperature on Fermi function. 2
Show that the average energy of an electron in an electron gas at 0 K is
35
where is the Fermi energy at 0 K. 5
H H H
PHY/IV/EC/07/340 7 8G—300
2 0 1 8
CBCS
4th Semester
PHYSICS
FOURTH PAPER
Atomic, Nuclear Physics-I and Solid State Physics—I
Full Marks 75
Time 3 hours
PART A—OBJECTIVE
Marks 25
The figures in the margin indicate full marks for the questions
SECTION—A
Marks 10
Tick the correct answer in the brackets provided 1×10=10
1. If EP and EK are the potential and kinetic energy of an electron in the
stationary orbit in hydrogen atom, the value of EP /EK is
2
1
2. Ka characteristic X-ray refers to the transition from
n 2 to n
n 3 to n 2
n 3 to n
n 4 to n 2
/340 1 Contd.
3. Complete the nuclear reaction 17
35
16
32
2
Cl L® S He4
1
H1
0
n1
1
H2
0
e1
4. If each fission of 92
U235 releases an energy of 200 MeV, how many fissions
must occur per second to produce a power of 32 ´106
3 × 2 ´1018
32 ´1018
1018
1020
5. The coordination number for closed packed crystal structure is
4
8
12
16
6. Miller indices for octahedral plane in cubic crystal is
0
1
1
None of the above
PHY/IV/EC/07/340 2 Contd.
7. X-ray diffraction patterns are used for studying crystal structure of solids
because
they have very high energy, hence they can penetrate through
solids
they are electromagnetic radiation, and hence do not interact with
matter (crystal)
their wavelengths are comparable to interatomic distances
their high frequency enables rapid analysis
8. Which one of the following is not a strong bond?
van der Waals bond
Covalent bond
Metallic bond
Ionic bond
9. The ratio of Fermi energy EF to Fermi temperature TF is equal to
Planck's constant
Boltzmann's constant
Universal gas constant
Rydberg's constant
10. The average kinetic energy of electrons in metals at 0 K is
1
2
mv2
KT
3
5
NeF
3
5
eF
PHY/IV/EC/07/340 3 Contd.
SECTION—B
Marks 15
Answer the following questions 3×5=15
1. State Pauli's exclusion principle, and hence deduce the maximum number
of electrons which can occupy a given shell.
OR
State the advantage and failure of Aston's mass spectrograph.
2. Mention the properties of b and g rays.
OR
In the b-decay, what is the significance of the emission of an antineutrino or
absorption of a neutrino?
3. What are crystal planes? Draw the crystal plane with intercepts
OR
Define lattice parameters. How do you identify a crystal system using lattice
parameters?
4. What are X-rays? What energy of wavelength must they have if they are to
be used in diffraction experiments for the purpose of characterizing crystal
structure?
OR
The Madelung constant of a stable solid is always positive. Why must that
be so?
5. State and explain Wiedemann-Franz law.
OR
Define Fermi velocity.
PHY/IV/EC/07/340 4 Contd.
PART B—DESCRIPTIVE
Marks 50
The figures in the margin indicate full marks for the questions
1. Define Compton effect. Derive an expression for the change in
wavelength when an incident radiation of wavelength l is scattered by a
free electron at an angle q.
Both photoelectric effect and Compton effect arise due to the action of
photons on electrons, but the two effects are not same. Explain this. 3
OR
Give the construction and working of Bainbridge's spectrograph. 7
Mention three interesting uses of mass spectrograph. 3
2. State radioactive decay law, and hence derive the decay equation. Give
the significance of decay constant l.
Show that the density of a nucleus is independent of its mass number. 2
Write a short note on 'Radio Carbon Dating'. 4
OR
What is the source of stellar energy? Explain the carbon-nitrogen cycle
reactions responsible for the stellar energy.
Explain how nuclear fission differs from nuclear fusion. 2
It is estimated that the energy released in the atomic bomb explosion
at Hiroshima was about 7 × 6 ´1013J. If on the average 200 MeV energy
was released on fission of one 92
U235 atom, calculate—
the number of uranium atoms fissioned;
the mass of uranium used for the bomb. 3
PHY/IV/EC/07/340 5 Contd.
3. What is packing factor? Determine the atomic packing factor of FCC
lattice.
Discuss Bravais lattice in three-dimensional crystal. 5
OR
Distinguish between primitive cell, non-primitive cell and conventional
cell. 3
What are Miller indices? How are they determined? Show that in a
cubic crystal the spacing between consecutive parallel planes of Miller
indices is given by
d a
h k l
hkl
2 2 2
4. What do you mean by lattice constant and coordination number? 2
How do you determine the Madelung constant for a NaCl crystal? 3
Derive Laue's equations and hence deduce Bragg's law of X-ray
diffraction. 5
OR
How would you compare van der Waals' bonds, ionic bonds and
covalent bonds? 3
What do you mean by reciprocal lattice vector? Derive the relation
between direct and reciprocal lattice vectors.
Write a brief note on concept of cohesive energy. 2
PHY/IV/EC/07/340 6 Contd.
5. Deduce Dulong and Petit's law for specific heat of solids from the
concept of harmonic oscillator. Discuss the agreement of the result with
that of the experiment.
Discuss Einstein's theory of specific heat of solids. 5
OR
Define Fermi energy and Fermi temperature. How are they related? 3
Using Fermi-Dirac distribution function, explain the effect of
temperature on Fermi function. 2
Show that the average energy of an electron in an electron gas at 0 K is
35
where is the Fermi energy at 0 K. 5
H H H
PHY/IV/EC/07/340 7 8G—300