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A current of 5A is… (Class 12 Physics SQP 2026-27, Q12)

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

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

From the official CBSE sample question paper for 2026-27, section A, question 12, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q12 · 1 mark · MCQMoving Charges and Magnetism

A current of 5A is passing through a long wire which has semicircular loop of radius 10 cm as shown in the figure. The magnetic field produced at the center of the loop is-

  1. (A)T
  2. (B)T
  3. (C)T
  4. (D)T

Figure in the paper: A long straight wire carrying 5 A from the left, with a semicircular loop (radius 10 cm marked by an arrow from centre to arc) in the middle, then continuing as a straight wire to the right. See it in the official paper.

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

A full circular loop gives at its centre; a semicircle gives half of that.

Hint 2

Convert 10 cm to metres before substituting.

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 straight parts point towards the centre (their lines pass through it), so they give no field there. Only the semicircle contributes: .

    ½ mark

  2. Substituting: T T. Option (C).

    ½ mark

Answer: T, option (C)

Where the marks are

  • Uses for the semicircle and gets T (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Moving Charges and Magnetism, 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.