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A point charge +Q is… (Class 12 Physics SQP 2026-27, Q1)

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PhysicsCBSE Class 12 · Sample paper, session 2026-27 · 1 mark · MCQ

CBSE Class 12 Physics sample paper 2026-27: question 1

From the official CBSE sample question paper for 2026-27, section A, question 1, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q1 · 1 mark · MCQElectric Charges and Fields

A point charge is placed at the centre of a spherical Gaussian surface of radius . If the radius of the sphere is doubled, the electric flux through the surface will

  1. (A)become half
  2. (B)become double
  3. (C)remain the same
  4. (D)become four times

Source: official sample paper from cbseacademic.nic.in (PDF). See it in the full Sample paper 2026-27.

Hints

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

Hint 1

Recall Gauss's law for a closed surface.

Hint 2

Does the charge inside the surface change when the radius changes?

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. By Gauss's law, , which depends only on the charge enclosed. It does not depend on the size of the surface.

    ½ mark

  2. Doubling leaves the enclosed charge unchanged, so the flux remains the same. Option (C).

    ½ mark

Answer: Remains the same, option (C)

Where the marks are

  • Uses Gauss's law: flux depends only on the enclosed charge, so it is unchanged (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Electric Charges and Fields, one at a time, marked against the answer key and marking points.Back to the full paperSample paper 2026-27: 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.