Worksheets1st unit Nuclear and particle physics-2023
Total questions: 42
Worksheet time: 33mins
The volume of a nucleus in an atom is proportional to the
mass number
proton number
neutron number
electron number
The order of magnitude of the binding energy per nucleon in a nucleus is
100 MeV
10 MeV
1 MeV
0.1 MeV
The following histogram represents the binding energy per particle (B.E./A) in MeV as a function of the mass number A of a nucleus. A nucleus with mass number A= 180 fissions into two nuclei of equal masses. In the process
180 MeV of energy is released.
180 MeV of energy is absorbed
360 MeV of energy is released
360 MeV of energy is absorbed
Two spherical nuclei A and B have mass numbers 216 and 64 respectively. The ratio of radius of nucleus A to B is
1.0
2.0
1.5
2.5
Nuclear forces are
spin dependent and have no non-central part
spin dependent and have a non-central part
spin independent and have no non-central part
spin independent and have a non-central part
With reference to nuclear forces which of the following statements is NOT true? The nuclear forces are
short range
charge independent
velocity dependent
spin independent
A heavy nucleus is found to contain more neutrons than protons. This fact is related to which one of the following statement
the nuclear force between neutrons is stronger than that between protons
the nuclear force between protons is of a shorter range than those between neutrons, so that a s maller
number of protons are held together by the nuclear force.
protons are unstable, to their number in a nucleus diminishes.
it costs more energy to add a proton to a (heavy) nucleus, than a neutron because of the Coulomb repulsion between protons
As one moves along the line of stability from Fe to U nucleus, the nuclear binding energy per particle decreases from about 8.8 MeV to 7.6 MeV. This trend is mainly due to the
short range nature of the nuclear forces.
long range nature of the coulomb forces
tensor nature of the nuclear forces
spin dependence of the nuclear forces.
The "magic numbers" for atoms are
numbers of electrons that confer atomic stability.
numbers of protons and/or neutrons that confer nuclear stability.
n/p ratios that confer nuclear stability.
atomic masses that confer nuclear stability.
atomic masses that indicate fissile isotopes.
Which isotope below has the highest nuclear binding energy per gram? (Note- numerical no. represent the mass number)
4He
16O
32S
55Mn
238U
Which of the following statements is incorrect?
Mass defect is the amount of matter that would be converted into energy if a nucleus were formed from initially separated protons and neutrons.
Nuclear binding energy is the energy released in the formation of an atom from subatomic particles.
Nuclei with highest binding energies are the most stable nuclei.
Einstein postulated the Theory of Relativity in which he stated that matter and energy are equivalent.
Mass number is the sum of all protons and electrons in an atom.
What is the binding energy of hydrogen nucleus?
13.6 MeB
1.36 MeV
0 MeV
infinite
Mass defect per nucleon is
The binding energy of the nucleus
Packing fraction
The average energy of the nucleus
All of above are one and the same thing
Average energy required to remove one nucleon from the nucleus is called
Binding energy per nucleon
Energy of decay
Destruction energy
packing energy
A nucleus with A=235 splits into two nuclei of mass numbers in the ratio 1 : 2.The ratio of the radii of the new nuclei are
1 : 2
1 : 1.26
8 : 1
1.26 : 1
Which one of the following statements is correct?
The mass of the nucleus must be less than the sum of the masses of the constituent neutrons and protons.
The mass of the nucleus must be equal to the sum of the masses of the constituent neutrons and protons
The mass of the nucleus must be greater than the sum of the masses of the constituent neutrons and protons.
The mass of the nucleus must be equal to only the masses of the constituent neutrons .
In neutral atom, the electrons are bound to the nucleus by
Magnetic force
Electrostatic force
Friction force
Centripetal force
An atom with even number of protons (i) is more stable, (ii) possesses higher binding energy per nucleon, (iii) is fissionable with slow neutrons. Which of the following is/are true?
only i
i & ii
i & iii
All of these
According to proton-electron hypothesis, electrons are positioned:
inside the nucleus
outside the nucleus
both inside and outside the nucleus
at all of the above locations
The radius of a nucleus is how much smaller than that of an atom:
10 times
100 times
1,000 times
1,00,000 times
According to proton-neutron hypothesis, for an atom to be electrically neutral, the number of:
neutrons equals the number of electrons
protons equals the number of nucleons
protons equals the number of neutrons
protons equals the number of electrons
The Hydrogen-3 nucleus (also called Tritium) consists of:
two neutrons and one proton
two protons and one neutron
two neutrons and two protons
two neutrons and no protons
Isotopes are nuclei with:
same A and Z
same Z, different A
same A, different Z
Z greater than A
Which of the following particles has the smallest mass?
. Proton
Neutron
Electron
Nucleus
The atomic mass unit is defined as
the mass of a proton.
the mass of an electron
the mass of a hydrogen-1 atom.
one twelfth the mass of a carbon-12 atom.
On which side of the band of stability does beta plus occur
Left
right
Alpha decay occurs when
There are too many neutrons
The atomic number greater than 83
There are too many protons
The atom is stable
The liquid drop model of nucleus was developed by
Fermi
Rutherford
Bohr, Wheeler
George Gamow
Liquid drop model classified as
semiclassical and collective
Quantum mechanical and collective
semiclassical and independent particle
Quantum mechanical and independent particle
Shell model classified as
semiclassical and collective
Quantum mechanical and collective
semiclassical and independent particle
Quantum mechanical and independent particle
Which of the following are correct for liquid drop model
The force of attraction between the nuclear surfaces is similar to the force of surface tension on
the surface of the liquid drop
density of the nuclear matter is dependent of its volume
The nuclear force saturates
The nuclear interactions between protons and protons, between protons and neutrons, and
between neutrons and neutrons appears to be identical, so the nuclear force is identical for every
nucleons
The mean free path of nucleons in nuclear matter is smaller than the nuclear diameter
As we move to the heavier nuclei, there is increase in number of protons which
tend to decrease the binding energy due to Coulomb repulsion between them. To compensate this Coulomb repulsion a term is added in the semi-empirical mass formula is
Coulomb energy term
Asymmetry energy term
Pairing energy term
Shall Correction Energy Term
The fact that a pair of like nucleons
is more strongly bound than pair of unlike nucleons. For this a term is added in the semi-empirical mass formula is
Coulomb energy term
Asymmetry energy term
Pairing energy term
Shall Correction Energy Term
A represents
volume energy term
surface energy term
Coulomb energy term
Asymmetry energy
B represents
volume energy term
surface energy term
Coulomb energy term
Asymmetry energy
D represents
volume energy term
surface energy term
Coulomb energy term
Asymmetry energy
Nuclear mean field is
The interaction between the nucleons in nuclei averages out that result in a potential which depends on its position and time
The interaction between the nucleons in nuclei averages out that result in a potential which depends only
on its time but does not depend on position
The interaction between the nucleons in nuclei averages out that result in a potential which depends only
on its position but does not depend on time
The interaction between the nucleons in nuclei averages out that result in a potential which depends only
neither on its position and time
Which of the followings is/are correct about magic numbers?
Nuclei with magic numbers of neutrons and protons have their first excited state at higher energies than for other neighbouring nuclei
Excitation probabilities of the first excited state are low for nuclei with magic numbers of neutrons and protons
Separation energy of a neutron and proton from a nucleus containing a magic number of neutron or proton is large compared to that for a nucleus containing one more neutron and proton
The number of stable isotopes of an element containing magic number of protons is usually large compared to those others elements
The spin-orbit term makes the nuclear potential well wider for nucleons with spin parallel to the orbital angular momentum and less wide for nucleons with spin opposite to the orbital angular momentum.
True
False
Experimentally the Woods-Saxon potential is found to be most realistic potential, however it is able to account for the first three magic numbers (2, 8, 20) only
True
False
Achievements of nuclear shell model is/are
It Explains nuclear spin and parity.
It explains magnetic moments for lighter nuclei.
It speaks about excited states of nuclei.
It predict magnetic dipole moment for heavier nuclei.
Which nucleus is the most stable?
16O
17O
15O
18O
