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Two long parallel wires kept 2… (Class 12 Physics 2023, Q2)

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PhysicsCBSE Class 12 · Board exam 2023, set 55/5/1 · 1 mark · MCQ

CBSE Class 12 Physics 2023: question 2

Set in the CBSE Class 12 board exam of 2023, paper 55/5/1, section A, question 2, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q2 · 1 mark · MCQMoving Charges and Magnetism

Two long parallel wires kept 2 m apart carry 3A current each, in the same direction. The force per unit length on one wire due to the other is

  1. (A) Nm, attractive
  2. (B) N/m, repulsive
  3. (C) N/m, repulsive
  4. (D) N/m, attractive

Source: official question paper from cbse.gov.in (PDF). See it in the full 2023 board paper, set 55/5/1.

Hints

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

Hint 1

Use the force per unit length between parallel currents.

Hint 2

Like (same-direction) currents attract each other.

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. N/m.

  2. Currents in the same direction attract, so the force is N/m, attractive. None of the options matches.

    1 mark

Answer: 9 × 10⁻⁷ N/m, attractive; no option is correct

Where the marks are

  • Mark awarded to every candidate since no option is correct (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 paper2023 board paper, set 55/5/1: 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.