Nuclei — Class 12 Physics PYQs

Which of the following figures correctly represent the shape of curve of binding energy per nucleon as a function of mass number ?
(A) [Graph]
(B) [Graph]
(C) [Graph]
(D) [Graph]

Define 'Mass defect' and 'Binding energy' of a nucleus. Describe 'Fission process' on the basis of binding energy per nucleon.
(b) A deuteron contains a proton and a neutron and has a mass of 2.013553 u. Calculate the mass defect for it in u and its energy equivalence in MeV. ($m_p=1.007277$ u, $m_n=1.008665$ u, 1u = 931.5 MeV/$c^2$)

Show the variation of binding energy per nucleon with mass number. Write the significance of the binding energy curve.
(b) Two nuclei with lower binding energy per nucleon form a nuclei with more binding energy per nucleon.
(i) What type of nuclear reaction is it ?
(ii) Whether the total mass of nuclei increases, decreases or remains unchanged ?
(iii) Does the process require energy or produce energy ?

The carbon isotope ${}_6^{12}$C has a nuclear mass of 12.000000 u. Calculate the binding energy of its nucleus. Given m${}_p$ = 1.007825 u; m${}_n$ = 1.008665 u.

Calculate the energy released/absorbed in the following nuclear reaction :
${}_6^{12}$C + ${}_6^{12}$C $\to$ ${}_{10}^{20}$Ne + ${}_2^4$He
Given : m(${}_6^{12}$C) = 12.000000 u
m(${}_{10}^{20}$Ne) = 19.992439 u
m(${}_2^4$He) = 4.002603 u
1 u = 931 MeV/c${}^2$

Briefly discuss three characteristics of the forces between nucleons.
(b) Which out of ${}_4^8$X and ${}_3^5$Y nuclei is more stable and why ?

Plot a graph depicting potential energy of a pair of nucleons in a nucleus as a function of their separation.
(b) Identify the regions where the nuclear force is (i) attractive, and (ii) repulsive. Justify your answer.

Write two characteristic properties of nuclear force.
(b) Draw a plot of potential energy of a pair of nucleons as a function of their separation. Write two important conclusions that can be drawn from the plot.

State any two properties of a nucleus.
(b) Why is the density of a nucleus much more than that of an atom ?
(c) Show that the density of the nuclear matter is the same for all nuclei.

The mass defect in a nuclear fusion reaction is 0.05%. What amount of energy will be liberated in one kg of fusion reaction ?