Skip to content

The ratio of the… (Class 12 Physics SQP 2025-26, Q11)

questionbuddy.in/q/cbse-12-physics-2025-26-sqp-q11-ratio-nuclear-densities-nuclei-having

PhysicsCBSE Class 12 · Sample paper, session 2025-26 · 1 mark · MCQ

CBSE Class 12 Physics sample paper 2025-26: question 11

From the official CBSE sample question paper for 2025-26, section A, question 11, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q11 · 1 mark · MCQNuclei

The ratio of the nuclear densities of two nuclei having the mass numbers 8 and 27 is

  1. (A)8:27
  2. (B)3:2
  3. (C)2:3
  4. (D)1:1

Source: official sample paper from cbseacademic.nic.in (PDF). See it in the full Sample paper 2025-26.

Hints

Open one hint at a time and try again before the next.

Hint 1

How does nuclear radius vary with mass number?

Hint 2

Compare how mass and volume each scale with .

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

  1. Nuclear radius is , so the volume is proportional to , the same as the mass.

  2. Density = mass/volume is therefore independent of , so the ratio is 1 : 1. Option (D).

    1 mark

Answer: 1:1, option (D)

Where the marks are

  • Uses to show the density is independent of (1 mark)

Revise the chapter

  • Chapter: Nuclei (notes, formulas, where marks are lost and every past question)
Practise this chapterBoard-style questions from Nuclei, one at a time, marked against the answer key and marking points.Back to the full paperSample paper 2025-26: every question, by section.

The question is transcribed from the official paper; figures are described in words. The solution, hints and chapter tag are ours. Spotted an error? Write tosupport@questionbuddy.in.