CBSE Class 12th Physics Chapter 13 - Nuclei Important Questions with Answers

You should focus on solving CBSE Class 12th Physics Chapter 13: Nuclei important questions, especially to help you score high marks. By solving CBSE Class 12th Physics 13 questions, you will be solving exam-oriented questions only.

Never Miss an Exam Update

CBSE Class 12th Physics Chapter 13 - Nuclei includes the following topics: Composition and size of a nucleus, nuclear force, Mass-energy relation, mass defect, binding energy per nucleon and its variation with mass number, nuclear fission, nuclear fusion. Unit 8, along with unit 7, that is, Dual Nature of Radiation and Matter, carries a total of 8 marks in the question paper. The Physics question paper will consist of MCQs, very short answer type questions, short answer type questions, passage-based questions, source-based questions, cartoon-based questions, and long answer type questions. The question paper will also include numerals based on the different chapters included in the curriculum. You are required to actively prepare for all these questions by downloading the latest sample question papers uploaded on the official website of the CBSE Academics at cbseacademics.nic.in.

To help the students with their preparations, we have shared some important questions below. These questions will not only help the students to revise their syllabus but also make them aware of the commonly asked topics during the board exams. The questions given below are derived from the important topics from chapter 13 of the Physics syllabus. Since “Atoms and Nuclei” is an important unit to be studied thoroughly, you need to also revise it actively to perform your best during the board exams. After completing your syllabus, you can pick up sample question papers and previous years' question papers uploaded online. Since Physics is a practical subject, you are required to also give importance to the practical exam, which will be conducted before the theory exam. Do not forget to check the practical syllabus from the official syllabus PDF.

According to the date sheet released by CBSE, the class 12th board exams will be conducted from 15th February 2025. You can now download the latest date sheet by visiting the official website of CBSE and prepare to appear for the board exams according to the exam dates mentioned there. Always keep an eye out on the official website of CBSE to catch all the latest updates regarding the curriculum and date sheet. Check the CBSE Class 12th Physics Chapter 13 - Nuclei Important Questions with Answers here:

Are you feeling lost and unsure about what career path to take after completing 12th standard?

Say goodbye to confusion and hello to a bright future!

Was this article helpful?

0 Upvotes

0 Downvotes

Write two characteristic features of nuclear force.
(b) Draw a plot of potential energy of a pair of nucleons as a function of their separation. (Comptt. All India 2017)

Question 2.

Two radioactive samples, X, Y have the same number of atoms at t = 0. Their half lives are 3h and 4h respectively. Compare the rates of disintegration of the two nuclei after 12 hours. (Comptt All India 2017)

Question 3.

Distinguish between nuclear fission and fusion. Explain how the energy is released in both the processes. (Comptt. All India 2017)

Question 4.

(a) Write the basic nuclear process involved in the emission of ?⁺ in a symbolic form, by a radioactive nucleus.
(b) In the reactions given below :
Important Questions for Class 12 Physics Chapter 13 Nuclei Class 12 Important Questions 71

Find the values of x, y, and z and a, b and c. (All India 2017)

Question 5.

Obtain the relation \(\mathbf{N}=\mathbf{N}_{0} e^{-\lambda t}\) for a sample of radioactive material having decay constant ?, where N is the number of nuclei present at constant ?. Hence obtain the relation between decay constant ? and half life \(\mathbf{T}_{\frac{1}{2}}\) of the sample. (Comptt. Delhi 2017)

Question 6.

(i) A radioactive nucleus ‘A’ undergoes a series of decays as given below:

The mass number and atomic number of A₂ are 176 and 71 respectively.
Determine the mass and atomic numbers of A₄ and A.

(Delhi 2017)

Question 7.

(a) Draw a graph showing the variation of binding energy per nucleon (BE/A) vs mass number A for the nuclei in 20 ? A ? 170.
(b) A nucleus of mass number 240 and having binding energy/nucleon 7.6 MeV splits into two fragments Y, Z of mass numbers 110 and 130 respectively. If the binding energy/ nucleon of Y, Z is equal to 8.5 MeV each, calculate the energy released in the nuclear reaction. (Comptt. All India 2017)

Question 8.

A radioactive nucleus ‘A’ undergoes a series of decays according to the following scheme:

The mass number and atomic number of A are 190 and 75 respectively. What are these numbers for A₄? (Delhi 2016)

Question 9.

(a) The mass of a nucleus in its ground state is always less than the total mass of its constituents – neutrons and protons. Explain.
(b) Plot a graph showing the variation of potential energy of a pair of nucleons as a function of their separation. (All India 2016)

Question 10.

A heavy nucleus X of mass number 240 and binding energy per nucleon 7.6 MeV is split into two fragments Y and Z of mass numbers 110 and 130. The binding energy of nucleons in Y and Z is 8.5 MeV per nucleon. Calculate the energy Q released per fission in MeV. (Delhi 2016)

Question 1.

Draw a plot of potential energy of a pair of nucleons as a function of their separation. Write two important conclusions which you can draw regarding the nature of nuclear forces. (All India 2016)

Question 2.

Draw a plot of the binding energy per nucleon as a function of mass number for a large number of nuclei, 2 ? A ? 240. How do you explain the constancy of binding energy per nucleon in the range 30 < A < 170 using the property that nuclear force is short-ranged? (All India 2016)

Question 3.

Important Questions for Class 12 Physics Chapter 13 Nuclei Class 12 Important Questions 32

(Delhi 2016)

Question 4.

Calculate the energy in fusion reaction :
Important Questions for Class 12 Physics Chapter 13 Nuclei Class 12 Important Questions 34

(Delhi 2016)

Question 5.

If both the number of protons and the number of neutrons are conserved in each nuclear reaction, in what way is mass converted into energy (or vice-versa) in a nuclear reaction? Explain. (Comptt. All India 2016)

Question 6.

Distinguish between nuclear fission and fusion. Show how in both these processes energy is released.
Calculate the energy release in MeV in the deuterium-tritium fusion reaction :
Important Questions for Class 12 Physics Chapter 13 Nuclei Class 12 Important Questions 66

Important Questions for Class 12 Physics Chapter 13 Nuclei Class 12 Important Questions 66

(Delhi 2015)

Question 7.

(a) Write three 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 graph. (All India 2015)

Question 8.

Important Questions for Class 12 Physics Chapter 13 Nuclei Class 12 Important Questions 56

(Delhi 2014)

Question 9.

Write the relation for binding energy (BE) (in MeV) of a nucleus of \(_{Z}^{A} N\), atomic number (Z) and mass number (A) in terms of the masses of its constituents – neutrons and protons.
(b) Draw a plot of BE/A versus mass number A for 2 ? A ? 170. Use this graph to explain the release of energy in the process of nuclear fusion of two light nuclei. (Comptt. Delhi 2014)

Question 10.

(a) Define the term ‘activity of a sample of radioactive nucleus. Write its S.I. unit.
Important Questions for Class 12 Physics Chapter 13 Nuclei Class 12 Important Questions 59