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Assertion (A): For… (Class 12 Physics SQP 2025-26, Q16)

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

CBSE Class 12 Physics sample paper 2025-26: question 16

From the official CBSE sample question paper for 2025-26, section A, question 16, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q16 · 1 mark · Assertion-reasonCompetency-basedElectric Charges and Fields

Assertion (A): For three point charges to be in equilibrium, they must be collinear.
Reason(R): One of the three charges must have different polarity than rest of the two.

  1. (A)Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
  2. (B)Both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
  3. (C)Assertion is true but Reason is false.
  4. (D)Both Assertion and Reason are false.

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

Two forces can cancel only if they lie along the same line.

Hint 2

Does the sign condition explain the collinearity?

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. The forces on each charge must cancel, which is possible only if they act along one line. So the charges must be collinear and the assertion is true.

  2. The middle charge must have opposite polarity to the other two, so the reason is true. However, it does not explain why the charges must be collinear. Option (B).

    1 mark

Answer: Option (B)

Where the marks are

  • Judges both statements true but R not explaining collinearity (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 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.