Class 12 Physics — Chapter 13: Nuclei
90 practice questions · 30 Easy · 30 Medium · 30 Hard
Practise Class 12 Physics Chapter 13, "Nuclei", with 90 NCERT-aligned multiple-choice questions. The set is split into 30 Easy, 30 Medium and 30 Hard questions, so you can warm up on the fundamentals and then push into the exam-level problems that separate top scorers in CBSE Board exams, JEE Main, JEE Advanced and NEET UG.
"Nuclei" is one of the chapters where numerical problem-solving, derivations and conceptual application really pays off. Each MCQ on this chapter is timed and uses exam-grade marking (+2 correct, −1 wrong, 0 skipped), training the same accuracy-under-pressure that real papers demand. Every question carries a short explanation, so a wrong answer becomes a quick lesson rather than a dead end — the fastest way to close gaps before a test.
Use this chapter as targeted revision: attempt the Easy set first to confirm your basics on Nuclei, then move to Medium and Hard to test application and problem-solving. Your accuracy, streaks and XP save automatically, and the chapter feeds into your overall Class 12 Physics mastery score. A few sample questions are shown below; sign in free to practise all 90.
Key concepts: Nuclei (Class 12 Physics)
This chapter covers the size and composition of the nucleus, mass–energy equivalence, binding energy, radioactivity, and nuclear fission and fusion.
- Nuclear composition & size
- The nucleus contains protons and neutrons (nucleons); its radius R = R₀A^{1/3}, so nuclear density is nearly constant.
- Mass defect & binding energy
- The nucleus has slightly less mass than its nucleons; the missing mass (mass defect) appears as binding energy via E = mc².
- Binding energy per nucleon
- Peaks around iron (~8.8 MeV); higher means more stable. Its shape explains why fission and fusion release energy.
- Radioactivity
- Unstable nuclei emit α, β or γ radiation; decay follows N = N₀e^{−λt} with half-life T = 0.693/λ.
- Fission & fusion
- Fission splits a heavy nucleus; fusion joins light nuclei — both move toward the high-binding-energy region, releasing energy.
Key formulas — Nuclei
💡 Exam tips for Nuclei
- Energy is released when the products have higher binding energy per nucleon than the reactants.
- Half-life and decay constant are linked by T₁/₂ = 0.693/λ — convert between them as needed.
Sample questions
Nucleons are:
Particles in the nucleus.
α-particle is:
⁴He²⁺.
Mass defect Δm relates to binding energy as:
Einstein mass-energy equivalence.
Nuclei — FAQs
What are the key concepts in Class 12 Physics Nuclei?+
This chapter covers the size and composition of the nucleus, mass–energy equivalence, binding energy, radioactivity, and nuclear fission and fusion. Key ideas include Nuclear composition & size, Mass defect & binding energy, Binding energy per nucleon, Radioactivity, Fission & fusion.
What does Class 12 Physics Chapter 13 (Nuclei) cover on XamBaaz?+
It covers 90 NCERT-aligned MCQs on "Nuclei" — 30 Easy, 30 Medium and 30 Hard — each with a timed quiz and an instant explanation, suitable for CBSE Board exams, JEE Main, JEE Advanced and NEET UG.
Are these "Nuclei" questions free to practise?+
Yes — sign in with Google to practise "Nuclei" free. Full unlimited access is ₹999/year (limited-time launch price), with no per-chapter charges.
How should I revise "Nuclei" for the exam?+
Start with the Easy quiz to confirm your fundamentals, then attempt Medium and Hard for application-level practice. Review each explanation, retry the questions you miss, and track your accuracy on this chapter until it is consistently high.
Practise all 90 questions free
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