Explore: All CBSE Class 12 chapters · CBSE Class 12 Physics PYQs · CBSE Class 12 hub · Syllabus & pattern · Class 12 2026
Answer first
Nuclei PYQs (previous year questions) for CBSE Class 12: Nuclei (Physics) had 15 questions across the 50 official CBSE Class 12 papers we tagged (2016–2026), and appeared in 10 of them. Asked in 10 of 10 years. The concepts asked in the most papers: Binding Energy, Radioactive Decay, Nuclear Size.
Year-wise question count
Asked in 10 of 10 years.
Most-asked concepts
Sorted by the number of papers a concept appeared in.
| Concept | Questions | Papers | Years |
|---|---|---|---|
| Binding Energy | 5 | 3 | 2025, 2020, 2018 |
| Radioactive Decay | 3 | 3 | 2020, 2019, 2016 |
| Nuclear Size | 2 | 2 | 2023, 2020 |
| Mass Defect | 1 | 1 | 2026 |
| Nuclear Density | 1 | 1 | 2024 |
| Nuclear Fission | 1 | 1 | 2017 |
| Nuclear Force | 1 | 1 | 2026 |
| Nuclear Fusion | 1 | 1 | 2022 |
How to practise Nuclei PYQs
- Start with the concepts at the top of the table. They have come back the most.
- Solve one year’s Nuclei questions from the official PDF against the clock, then check the answer listed below.
- Log every miss as a concept gap, a calculation slip or a misread. Each needs a different fix.
- Once a concept is clean in two papers, move to the next. Then sit a full paper from the year pages.
Questions by year
Each line gives the question number and paper, type, concept, our one-line summary, with a link to the official PDF.
CBSE Class 122026
CBSE Class 122025
CBSE Class 122024
- Q.28 (Physics (55/1/1)) · Short answer · Nuclear Density: Nuclear properties; why nuclear density is high and constant PDF
CBSE Class 122023
- Q.12 (Physics (55/1/1)) · MCQ · Nuclear Size: Dependence of nuclear mass density on mass number PDF
CBSE Class 122022
- Q.6 (Physics Term 2 (55/1/1)) · Short answer · Nuclear Fusion: Energy released in a deuterium-tritium fusion reaction PDF
CBSE Class 122020
- Q.18 (Physics (55/1/1)) · Very short answer · Nuclear Size: Nuclear radius of Cu-64 from that of Al-27 PDF
- Q.23 (Physics (55/1/1)) · Short answer · Radioactive Decay: Define half-life; activity ratio of two samples PDF
- Q.33 (Physics (55/1/1)) · Long answer · Binding Energy: Speed of alpha particle from binding energies in a decay PDF
CBSE Class 122019
- Q.21 (Physics (55/1/1)) · Short answer · Radioactive Decay: Define decay constant; half life and initial nuclei from decay rates PDF
CBSE Class 122018
CBSE Class 122017
- Q.23 (Physics (55/1)) · Value based · Nuclear Fission: Chernobyl reactor disaster, energy release process and values shown PDF
CBSE Class 122016
- Q.21 (Physics (55/1/N)) · Short answer · Radioactive Decay: Derive radioactive decay law and relate mean life to decay constant PDF
Other Physics chapters
- Electric Charges and Fields PYQs
- Electrostatic Potential and Capacitance PYQs
- Current Electricity PYQs
- Moving Charges and Magnetism PYQs
- Magnetism and Matter PYQs
- Electromagnetic Induction PYQs
- Alternating Current PYQs
- Electromagnetic Waves PYQs
- Ray Optics and Optical Instruments PYQs
- Wave Optics PYQs
- Dual Nature of Radiation and Matter PYQs
- Atoms PYQs
- Semiconductor Electronics PYQs
- Communication Systems PYQs
FAQ
How many Nuclei questions come in CBSE Class 12?
In the official papers we tagged: 2 in 2026, 2 in 2025, 1 in 2024, 1 in 2023, 1 in 2022, 3 in 2020, 1 in 2019, 2 in 2018, 1 in 2017 and 1 in 2016. That is 15 questions in all, about 5% of Physics.
Which Nuclei topics repeat in CBSE Class 12?
Asked in the most papers: Binding Energy, Radioactive Decay, Nuclear Size. The concept table lists every one with its count.
Are these official CBSE Class 12 questions?
Yes. Every question is from an official CBSE Class 12 paper hosted on our year pages. The one-line summaries are ours; open the PDF linked beside each question for the full text.