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Nuclei — NEET Physics MCQs

30 questions written by hand against the NCERT chapter. Every wrong option is explained, not just the right one.

30questions
10/14/6easy / medium / hard
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Sample questions from this chapter

The unified atomic mass unit, denoted by u, is defined as what fraction of the mass of a carbon-12 atom?
  1. One-twelfth ✓
  2. One-sixth
  3. One-fourteenth
  4. One-sixteenth
Answer: A. By definition, 1 u is exactly one-twelfth of the mass of one neutral carbon-12 atom in its ground state.
Why not B: One-sixth is twice the defined fraction and would not reproduce the standard atomic-mass scale.
Why not C: One-fourteenth incorrectly uses nitrogen's mass number instead of the carbon-12 reference standard.
Why not D: One-sixteenth resembles an oxygen-based scale but is not the modern definition of the unified unit.
A gold-197 nucleus has atomic number 79. How many neutrons does it contain?
  1. 79
  2. 197
  3. 118 ✓
  4. 276
Answer: C. Using N = A - Z gives N = 197 - 79 = 118 neutrons.
Why not A: Seventy-nine is the proton count Z; the neutron count requires subtracting Z from A.
Why not B: One hundred ninety-seven counts all nucleons and therefore includes both protons and neutrons.
Why not D: Adding A and Z double-counts the protons instead of isolating the neutron population.
Using R = R0 A^(1/3), what is the approximate ratio of the radius of gold-197 to that of silver-107?
  1. 1.23 ✓
  2. 1.84
  3. 0.54
  4. 3.39
Answer: A. The ratio is (197/107)^(1/3), which is approximately 1.23; the constant R0 cancels.
Why not B: This is close to the direct mass-number ratio, but radius depends on its cube root.
Why not C: This inverse mass-number ratio would also predict the heavier gold nucleus to be smaller.
Why not D: This resembles an incorrectly amplified power dependence rather than the cube-root scaling law.

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Every NCERT question in this chapter is solved, free: NCERT solutions — Nuclei →

Other NEET Physics chapters

Units and MeasurementMotion in a Straight LineMotion in a PlaneLaws of MotionWork Energy and PowerSystems of Particles and Rotational Motion

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Questions

How many NEET questions are there on Nuclei?

This chapter test has 30 questions — 10 easy, 14 medium and 6 hard — all written against the NCERT Class 12 chapter.

Is this NEET Physics chapter test free?

Yes. Every chapter test is free with no login, and you get your all-India rank on every one. Nothing on the site is on sale right now.

Do the questions explain the wrong options?

Yes — every distractor carries its own explanation naming the specific misconception that makes a student pick it. That is the part most question banks skip, and it is the part that changes your next attempt.