PHY/VI/10 Student's Copy
2 0 1 8
6th Semester
PHYSICS
TENTH PAPER
Nuclear Physics—II
Pre-revised
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. Isotones are nuclei with equal number of
neutrons protons
electrons shells
2. The charge of nucleus is due to the
electronic configuration neutrons
protons electrons
/490 1 Contd.
3. The average life of a radioactive substance and its decay constant are
directly proportional
reciprocal to each other
inversely proportional
not related
4. In radioactive carbon dating, which carbon isotope is used?
C-14 C-13
C-12 C-11
5. Ultra fast neutron has energy greater than
0·5 MeV 5 MeV
10 MeV 20 MeV
6. When effective neutron multiplication factor k then the nuclear chain
reaction is
not self-sustaining self-sustaining
increasing in rate None of the above
7. In linear accelerators, the length of the drift tubes must be proportional to
3 5 7 ... 4 8 16 ...
2 3 4 ... 2 3 4 ...
8. In 1952, Donald A. Glaser of United States invented the
ionisation chamber cloud chamber
scintillation chamber spark chamber
9. In cosmic rays, the penetrating ones are called
hard components soft components
primary rays secondary rays
10. How many quarks does baryon have?
1 2
3 4
PHY/VI/10 2 Contd.
SECTION—B
Marks 15
Answer the following questions 3×5=15
1. Write a note on nuclear charge.
2. What do you mean by half-life of radioactive nuclei?
3. Discuss in brief the origin of stellar energy.
4. Discuss in brief the accelerators in India.
5. Write a note on the concept of anti-particles.
PART B—DESCRIPTIVE
Marks 50
The figures in the margin indicate full marks for the questions
1. What is binding energy? Explain how binding energy affects the
stability of a nucleus. 5
Describe packing fraction. Write the relation between packing fraction
and mass defect. 5
OR
Explain the concept of nuclear spin. 2
Discuss semi-empirical mass formula and its simple application. 4
Draw and explain nuclear stability curve. 4
2. Discuss the different types of radioactive decays. 4
What are radioisotopes? Write the production and uses of
radioisotopes. 6
OR
Describe g-rays and their origin. 4
Explain the three types of b-decay processes. 6
PHY/VI/10 3 Contd.
3. Describe nuclear shell model in detail. 5
Discuss the discovery of neutron. Write the properties of neutron. 5
OR
Write the concept of critical size in nuclear fission reaction. 2
What do you mean by multiplication factor? 2
What is nuclear fusion? Explain how energy is released in fusion
reaction. 6
4. Describe the construction, characteristic, working and counting rate of
Geiger-Müller Counter. 10
OR
Explain the following in detail 5×2=10
Proportional counter
Cerenkov counter
5. What are primary and secondary cosmic rays? 2
Explain in detail the latitude effect of cosmic rays. 3
Discuss cosmic ray showers and explain the absorption of secondary
rays. 5
OR
What do you understand by leptons? How many leptons are there in
total? 4
Describe the following 2×3=6
Strangeness
Isospin
Hypercharge