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Physics - Nuclear Physics

Practise 165 JEE Main previous year questions on Nuclear Physics, compiled from papers spanning 2002 to 2026. Each question is pulled directly from the actual exam paper it appeared in, so you're practising in the exact style and difficulty JEE Main tests.

Nuclear Physics has been asked in 25 of the 25 years of JEE Main papers analysed (2002–2026), with 165 questions in all. 38% of them were easy, 49% moderate and 13% tough. Most of its questions came from 2021, with 22 questions that year. In the last three years (2024–2026) it had 34 questions across 49 papers, about 0.7 per paper.

The chapter's 4 topics are not weighted equally: Radioactivity (82 questions, 50%), Nuclear energy (37 questions, 22%), and Nuclear reactions (24 questions, 15%) have been asked the most. Radioactivity has also led over the last five years, with 27 questions. Radioactivity has produced the most tough questions (11).

  1. 1Two radioactive substances A and B of mass numbers and respectively, shows spontaneous -decay with same value of MeV. The ratio of energies 08 Apr, 2026 (E)Radioactivity
  2. 2The energy released when kg of is converted into by proton bombardment is eV. The value of is _______. (Nearest integer) (Mass of u, mass of06 Apr, 2026 (M)Nuclear energy
  3. 3The energy released if hydrogen atoms are combined to form is __________ MeV. (Take binding energies per nucleon of and as MeV and MeV, resp06 Apr, 2026 (E)Nuclear energy
  4. 4Assuming the experimental mass of as , the mass defect of atom is _______ . (Mass of proton , mass of neutron , and is the speed of the ligh05 Apr, 2026 (E)Nuclear energy
  5. 5Two nuclei of mass number combine with another nucleus of mass number to yield a nucleus of mass number . If the binding energy per nucleon 04 Apr, 2026 (M)Nuclear energy
  6. 6The binding energy per nucleon of is _______ MeV.02 Apr, 2026 (E)Nuclear energy
  7. 7An atom is bombarded by shower of fundamental particles and in 10 s this atom absorbed 10 electrons, 10 protons and 9 neutrons. The percenta28 Jan, 2026 (M)Nuclear structure
  8. 8A nucleus has mass number and radius . Another nucleus has mass number and radius . If then is:28 Jan, 2026 (E)Nuclear structure
  9. 9Given below are two statements: Statement I : For all elements, greater the mass of the nucleus, greater is the binding energy per nucleon. 24 Jan, 2026 (M)Nuclear energy
  10. 10The binding energy for the following nuclear reactions are expressed in MeV. If denote the stability of and , respectively, then the correct24 Jan, 2026 (E)Nuclear energy
  11. 11Which of the following pair of nuclei are isobars of the element?23 Jan, 2026 (E)Nuclear structure
  12. 12The average energy released per fission for the nucleus of is 190 MeV. When all the atoms of 47 g pure undergo fission process, the energy r23 Jan, 2026 (E)Nuclear reactions
  13. 13The minimum frequency of photon required to break a particle of mass 15.348 amu into particles is kHz. [mass of He nucleus = and ]22 Jan, 2026 (M)Nuclear energy
  14. 14-particle scatters from a target material of atomic number 79. From the given data the estimated diameter of nuclei of the target material i22 Jan, 2026 (M)Nuclear structure
  15. 15For a nucleus of mass number and radius , the mass density of nucleus can be represented as08 Apr, 2025 (E)Nuclear structure
  16. 16Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : The density of the07 Apr, 2025 (E)Nuclear structure
  17. 17A radioactive material P first decays into Q and then Q decays to non-radioactive material R. Which of the following figure represents time 04 Apr, 2025 (E)Radioactivity
  18. 18Match the LIST-I with LIST-II Choose the correct answer from the options given below :03 Apr, 2025 (M)Nuclear reactions
  19. 19Energy released when two deuterons fuse to form a helium nucleus is : (Given : Binding energy per nucleon of and binding energy per nucleon 02 Apr, 2025 (E)Nuclear energy
  20. 20Choose the correct nuclear process from the below options [p: proton, n : neutron, : electron, : positron, neutrino, : antineutrino]28 Jan, 2025 (M)Nuclear structure
  21. 21A radioactive nucleus has 3 times the decay constant as compared to the decay constant of another radioactive nucleus . If initial number of23 Jan, 2025 (M)Radioactivity
  22. 22Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : The binding energy23 Jan, 2025 (E)Nuclear energy
  23. 23The energy equivalent of of substance is :09 Apr, 2024 (M)Nuclear energy
  24. 24A star has helium composition. It starts to convert three into one via triple alpha process as . The mass of the star is and it generates en09 Apr, 2024 (M)Nuclear energy
  25. 25A nucleus at rest disintegrates into two smaller nuclei with their masses in the ratio of . After disintegration they will move :09 Apr, 2024 (E)Nuclear energy
  26. 26The energy released in the fusion of of hydrogen deep in the sun is and the energy released in the fission of of is . The ratio is approxima09 Apr, 2024 (E)Nuclear reactions
  27. 27Binding energy of a certain nucleus is . How much is the difference between total mass of all the nucleons and nuclear mass of the given nuc08 Apr, 2024 (M)Nuclear energy
  28. 28If is the mass of isotope and are the masses of proton and neutron, then nuclear binding energy of isotope is :08 Apr, 2024 (E)Nuclear energy
  29. 29In a hypothetical fission reaction The identity of emitted particles ( is :08 Apr, 2024 (E)Nuclear reactions
  30. 30If three helium nuclei combine to form a carbon nucleus then the energy released in this reaction is _____ . (Given , atomic mass of helium 05 Apr, 2024 (M)Nuclear reactions
  31. 31Which of the following nuclear fragments corresponding to nuclear fission between neutron and uranium isotope is correct :04 Apr, 2024 (M)Nuclear reactions
  32. 32The disintegration energy for the nuclear fission of is ______ . Given atomic masses of , Value of04 Apr, 2024 (E)Nuclear energy
  33. 33The radius of a nucleus of mass number 64 is 4 . 8 fermi. Then the mass number of another nucleus having radius of 4 fermi is 1000 x , where01 Feb, 2024 (M)Nuclear structure
  34. 34From the statements given below : (A) The angular momentum of an electron in n t h orbit is an integral multiple of h . (B) Nuclear forces d01 Feb, 2024 (E)Nuclear structure
  35. 35The mass number of nucleus having radius equal to half of the radius of nucleus with mass number 192 is:31 Jan, 2024 (E)Nuclear structure
  36. 36A nucleus has mass number A 1 and volume V 1 . Another nucleus has mass number A 2 and volume V 2 . If relation between mass number is A 2 =31 Jan, 2024 (E)Nuclear structure
  37. 37In a nuclear fission reaction of an isotope of mass M , three similar daughter nuclei of same mass are formed. The speed of a daughter nucle30 Jan, 2024 (E)Nuclear reactions
  38. 38The explosive in a Hydrogen bomb is a mixture of H 2 1 , H 3 1 and Li 6 3 in some condensed form. The chain reaction is given by Li 6 3 + n 29 Jan, 2024 (M)Nuclear reactions
  39. 39In a nuclear fission process, a high mass nuclide ( A ≈ 236 ) with binding energy 7 . 6 MeV / Nucleon dissociated into two middle mass nucli27 Jan, 2024 (M)Nuclear energy
  40. 40The atomic mass of C 12 6 is 12 . 000000 u and that of C 13 6 is 13 . 003354 u . The required energy to remove a neutron from C 13 6 , if ma27 Jan, 2024 (E)Nuclear energy
  41. 41The half-life of a radioactive nucleus is 5 years. The fraction of the original sample that would decay in 15 years is :15 Apr, 2023 (M)Radioactivity
  42. 4292 238 A 90 234 B + D 2 4 + Q In the given nuclear reaction, the approximate amount of energy released will be: [Given, mass of 92 238 A = 213 Apr, 2023 (M)Nuclear energy
  43. 43Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Assertion A : The binding energy per nu13 Apr, 2023 (E)Nuclear energy
  44. 44A common example of alpha decay is 238 92 U 234 90 Th + 2 He 4 + Q Given: 238 92 U = 238 . 05060 u 234 90 Th = 234 . 04360 u 4 2 He = 4 . 0012 Apr, 2023 (M)Radioactivity
  45. 45Two radioactive elements A and B initially have same number of atoms. The half life of A is same as the average life of B . If A and B are d11 Apr, 2023 (M)Radioactivity
  46. 46The decay constant for a radioactive nuclide is 1 . 5 10 - 5 s - 1 . Atomic weight of the substance is 60 g mole - 1 , N A = 6 10 23 . The a10 Apr, 2023 (M)Radioactivity
  47. 47The half life of a radioactive substance is T . The time taken, for disintegrating 7 8 t h part of its original mass will be:10 Apr, 2023 (E)Radioactivity
  48. 48For a nucleus X Z A having mass number A and atomic number Z A. The surface energy per nucleon ( b s ) = a 1 A 2 3 . B. The Coulomb contribu08 Apr, 2023 (M)Nuclear energy
  49. 49A nucleus with mass number 242 and binding energy per nucleon as 7 . 6 MeV breaks into two fragment each with mass number 121 . If each frag08 Apr, 2023 (M)Nuclear energy
  50. 50A radio active material is reduced to 1 8 of its original amount in 3 days. If 8 10 - 3 kg of the material is left after 5 days the initial 08 Apr, 2023 (E)Radioactivity

Frequently Asked Questions

1.How many questions are available for Nuclear Physics?

This chapter includes 165 questions compiled from JEE Main papers spanning 2002 to 2026.

2.Are these questions only from JEE Main, or from other exams too?

These are JEE Main questions specifically for the Nuclear Physics chapter. Questions from other exams like NTA Abhyas (JEE Main) or JEE Advanced are organised separately under their respective exam sections.

3.Is Nuclear Physics an important chapter for JEE Main Physics?

Nuclear Physics has appeared in 25 of the 25 years of JEE Main papers covered here, with 165 questions across 128 papers - about one per paper it appears in.

4.What is the difficulty level of Nuclear Physics questions in JEE Main?

Of the 165 questions analysed for this chapter, 38% are easy, 49% moderate and 13% tough. 2021 had the most, with 22 questions.

5.Which topics in Nuclear Physics should I focus on?

These topics have carried the most weightage in Nuclear Physics:

  • Radioactivity - 82 questions (50%)
  • Nuclear energy - 37 questions (22%)
  • Nuclear reactions - 24 questions (15%)
  • Radioactivity has produced the most tough questions (11).
6.Is Nuclear Physics's weightage in JEE Main going up or down?

Across all 128 papers analysed, Nuclear Physics has averaged about 1.3 questions per paper. In the last three years (2024–2026), that average has fallen, at about 0.7 questions per paper. Use the year-wise numbers on this page for the exact trend before you decide how much time to give it.