Nuclear And Particle Physics — Part 2 MCQs with Explanations

1.28 × 108 K is the correct answer to “The threshold temperature above which the thermonuclear reaction $${}_2^3{\text{He}} + {}_2^3{\text{He}} \to {}_2^4{\text{He}} + 2{}_1^1{\text{He}} + 12.86{\text{ MeV}}$$ can occur is (use e 2 /4πε 0 = 1.44 × 10 -15 MeV-m)”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

conservation of angular momentum is the correct answer to “Suppose that a neutron at rest in free space decays into a proton and an electron. This process would violate”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

v-1 is the correct answer to “A thermal neutron having speed v impinges on a 235 U nucleus. The reaction cross-section is proportional to”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

$$V\left( r \right) = - \frac{a}{r} + br$$ is the correct answer to “Which of the following functions describes the nature of interaction potential V(r) between two quarks inside a nucleon? (r is the distance between the quarks and a and b positive constants of suitable dimensions).”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

both proton and neutron are not elementary point particles is the correct answer to “The experimentally measured spin g factors of proton and a neutron indicate that”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

8 V is the correct answer to “An O 16 nucleus is spherical and has a charge radius R and a volume $${\text{V}} = \frac{4}{3}\pi {{\text{R}}^3}.$$ According to the empirical observations of the charge radii, the volume of the 54 128 Xe nucleus assumed to be spherical is”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

3/2 and odd is the correct answer to “The spin and parity of $${}_4^9{\text{Be}}$$ nucleus as predicted by the shell model are respectively”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

antiparallel to the nuclear spin directions is same as that along the nuclear spin direction is the correct answer to “The evidence for the non-conservation of parity β in β-decay has been obtained from the observation that the β intensity”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

1800 MeV is the correct answer to “The masses of a hydrogen atom, neutron and $${}_{92}^{238}{\text{U}}$$ are given by 1.0078, 1.0087 and 238.0508 respectively. The binding energy of $${}_{92}^{238}{\text{U}}$$ is therefore approximately equal to (taking 1 amu = 931.64 MeV)”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

$${}_7^{13}N \to {}_7^{13}C + {\beta ^ + } + {v_c}$$ is the correct answer to “Which one of the following nuclear reactions is possible”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

unequal number of protons and neutrons inside the nucleus is the correct answer to “The asymmetry terms in the Weizsacker semi-empirical mass formula is because of”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

uud is the correct answer to “In the quark model which one of the following represents a proton”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

5.17 is the correct answer to “A nucleus having mass number 240 decays by α-emission to the ground state of its daughter nucleus. The Q value of the process is 5.26 MeV. The energy (in MeV) of the α particle is”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

weak interactions is the correct answer to “A relativistic particle travels a length of 3 × 10 -3 m in air before decaying. The decay process of the particle is dominated by”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

The range of nuclear force is of the order of 10-15 m - 10-14 m is the correct answer to “Pick the wrong statement.”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

uus is the correct answer to “The strange Baryon $${\sum {} ^ + }$$ has the quark structure”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

$$\frac{{{1^ - }}}{2}$$ is the correct answer to “According to the shell model, the ground state of $${}_8^{15}{\text{O}}$$ nucleus is”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

zero and half integer is the correct answer to “The nuclear spins of $${}_6^{14}{\text{C}}$$ and $${}_{12}^{25}{\text{Mg}}$$ nuclei are respectively,”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

It costs more energy to add a proton to a (heavy) nucleus than a neutron because of the Coulomb repulsion between protons is the correct answer to “A heavy nucleus is found to contain more neutrons than protons. This fact is related to which one of the following statements:”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

$$\frac{1}{{\sqrt 2 }}\left( {\left| {np} \right\rangle - \left| {pn} \right\rangle } \right)$$ is the correct answer to “Let $$\left| n \right\rangle $$ and $$\left| p \right\rangle $$ denote the isospin state with $$I = \frac{1}{2},\,{I_3} = \frac{1}{2}$$ and $$I = \frac{1}{2},\,{I_3} = - \frac{1}{2}$$ of a nucleon respectively. Which one of the following two-nucleon states has $$I = 0,\,{I_3} = 0\,?$$”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

200 MeV and 10 MeV is the correct answer to “Typical energies released in a nuclear fission and a nuclear fusion reactions are respectively”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

The particle has a definite value of the square of the spin angular momentum is the correct answer to “In a Stern-Gerlach experiment, the magnetic field is in +Z direction. A particle comes out of this experiment in $$\left| { + {\bf{\hat z}} \uparrow > } \right.$$ state. Which of the following statements are true”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

a neutrino is the correct answer to “By capturing an electron, $${}_{25}^{54}{\text{M}}{{\text{n}}_{29}}$$ transforms into $${}_{25}^{54}{\text{C}}{{\text{r}}_{30}}$$ releasing”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

10 MeV is the correct answer to “The order of magnitude of the binding energy per nucleon in a nucleus is”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

from only one kind of radioactive nuclei having same half life is the correct answer to “The plot of log A vs time t, where A is activity as shown in the figure, corresponds to decay”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

long range nature of the Coulomb forces is the correct answer to “As one moves along the line of stability from 56 Fe to 235 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”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

hadrons only is the correct answer to “Weak nuclear forces act on”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

i. $${}_8^{16}{\text{O}}$$ nucleus; ii. nuclear spin $$J = \frac{1}{2}$$ is the correct answer to “The following gives a list of pairs containing i. a nucleus ii. one of its properties Find the pair which is inappropriate”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

13 up quarks and 14 down quarks is the correct answer to “The nucleus of the atom $${}_4^9{\text{Be}}$$ consists of”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.

4% is the correct answer to “To explain the observed magnetic moment of deuteron (0.8574 μ N ), its ground state wavefunction is taken to be an admixture of S and D states. The expectation values of the z component of the magnetic moment in pure S and pure D states are 0.8797 μ N and 0.3101 μ N respectively. The contribution of the D state to the mixed ground state is approximately”. This question is standard in competitive examination syllabi for Nuclear And Particle Physics.