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Physics - Nuclear Physics

Practise 18 NEST (NISER) previous year questions on Nuclear Physics, compiled from papers spanning 2012 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 NEST (NISER) tests.

Nuclear Physics has been asked in 13 of the 16 years of NEST (NISER) papers analysed (2011–2026), with 18 questions in all. 6% of them were easy, 67% moderate and 28% tough. Most of its questions came from 2021, with 3 questions that year. In the last three years (2024–2026) it had 4 questions across 4 papers, about 1 per paper.

The chapter's 3 topics are not weighted equally: Radioactivity (13 questions, 72%), Nuclear energy (3 questions, 17%), and Nuclear structure (2 questions, 11%) have been asked the most. Radioactivity has also led over the last five years, with 4 questions. Radioactivity has produced the most tough questions (5).

  1. 1Let be the mass number, be the atomic number and be the neutron number of a nucleus. Then the statement which is always true, is2026Nuclear structure
  2. 2If all the Helium-4 nuclei, each of mass 4.0026034 u , in the core of a star is converted to Carbon-12 nuclei, then the energy released in M2025Nuclear energy
  3. 3Assume that when undergoes fission, about 0.1 percent of the original mass is released as energy. When coal is burned, about of heat is libe2024 (Session 2)Nuclear energy
  4. 4The radius of nucleus of an isotope is . Assume that the number of protons and neutrons in the nucleus is same and the mass . The approximat2024 (Session 2)Nuclear structure
  5. 5Two radioactive samples and have the same number of atoms initially . The half life of is half the mean life of . Then is seven times when i2023 (Session 1)Radioactivity
  6. 6Two radioactive samples and have the same number of atoms initially . The half life of is half the mean life of . Then the ratio when is clo2023 (Session 2)Radioactivity
  7. 7A detector records 200 events from the decay of a radioactive sample in the first 10 s. It records 74 events in the next 10 s . The half lif2022 (Session 1)Radioactivity
  8. 8The number of radioactive nuclei in a sample is halved every 69 sec . Then, on an average the number of nuclei decaying per second is approx2022 (Session 2)Radioactivity
  9. 9The photon flux of a one curie gamma ray source incident on a human tissue of cross-sectional area decreases exponentially with tissue depth2021 (Session 1)Radioactivity
  10. 10A scientist found a specimen in which the decay constant of nuclei X and nuclei Y are and respectively. At the number of X and Y nuclei were2021 (Session 2)Radioactivity
  11. 11In a radioactive decay, Plutonium disintegrates to and an particle. After the disintegration the mass difference between the parent nucleus 2021 (Session 2)Radioactivity
  12. 12A radioactive dye of 4 grams is injected into the bloodstream of a patient. The half life of the dye is 6 hours. At the same time the dye is2020 (Session 2)Radioactivity
  13. 13has a half life of 5730 years and its abundance in the atmosphere is 1 in carbon atoms. A fresh sample of 0.001 mole of collected from the a2019 (Session 1)Radioactivity
  14. 14Consider the following decay schemes: The energies corresponding to X and Y with respect to are 1.088 MeV and 0.412 MeV respectively [Note t2017Radioactivity
  15. 15The activity of two radioactive nuclei and is plotted on a semi-log graph. The half-life and decay constant of and are and respectively. The2015Radioactivity
  16. 16Consider the sequential radioactive decay process: , with decay constants, and such that . At time the number of the species is and the numb2014Radioactivity
  17. 17The binding energy per nucleon of is 8 MeV and that of is 7.5 MeV where X represents an element. The minimum energy required to remove a neu2013Nuclear energy
  18. 18and are two radioactive substances. The half-life of is same as the average life of . The decay constant of is 3.33 per day. (assume )2012Radioactivity

Frequently Asked Questions

1.How many questions are available for Nuclear Physics?

This chapter includes 18 questions compiled from NEST (NISER) papers spanning 2012 to 2026.

2.Are these questions only from NEST (NISER), or from other exams too?

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

3.Is Nuclear Physics an important chapter for NEST (NISER) Physics?

Nuclear Physics has appeared in 13 of the 16 years of NEST (NISER) papers covered here, with 18 questions across 16 papers - about one per paper it appears in.

4.What is the difficulty level of Nuclear Physics questions in NEST (NISER)?

Of the 18 questions analysed for this chapter, 6% are easy, 67% moderate and 28% tough. 2021 had the most, with 3 questions.

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

These topics have carried the most weightage in Nuclear Physics:

  • Radioactivity - 13 questions (72%)
  • Nuclear energy - 3 questions (17%)
  • Nuclear structure - 2 questions (11%)
  • Radioactivity has produced the most tough questions (5).
6.Is Nuclear Physics's weightage in NEST (NISER) going up or down?

Across all 16 papers analysed, Nuclear Physics has averaged about 1.1 questions per paper. In the last three years (2024–2026), that average has stayed about the same, at about 1.0 questions per paper. Use the year-wise numbers on this page for the exact trend before you decide how much time to give it.