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Answer the following. (Class 10 Science SQP 2026-27, Q36)

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ScienceCBSE Class 10 · Sample paper, session 2026-27 · 3 marks · Short answer

CBSE Class 10 Science sample paper 2026-27: question 36

From the official CBSE sample question paper for 2026-27, section C, question 36, for 3 marks. Try it first; the hints and our step-by-step solution are below.

Q36 · 3 marks · Short answerMagnetic Effects of Electric Current

Answer the following.

  1. A

    State the Right-Hand Thumb Rule and describe how it helps determine the direction of magnetic field around a current-carrying conductor.

    0 marks
  2. B

    Explain how the magnetic field changes with distance from the conductor.

    0 marks

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

Think of gripping the wire with your right hand. Which finger shows the current?

Hint 2

What shape are the field lines around a straight wire, and how does their spacing change as you move outward?

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. A. Right-Hand Thumb Rule: Imagine holding a straight current-carrying conductor in your right hand so that the stretched thumb points in the direction of the (conventional) current. The fingers then wrap around the conductor in the direction of the magnetic field lines.

    1 mark

  2. How it helps: The field lines around a straight conductor are concentric circles. The rule tells us which way they circulate. Point the thumb along the current and read the direction of the curled fingers. For example, for current flowing upward the field is anticlockwise when viewed from above. If the current is reversed, the field direction also reverses.

    1 mark

  3. B. Variation with distance: The magnetic field due to a long straight conductor is strongest close to the wire and becomes weaker farther away. The concentric circles of field lines become more widely spaced. The magnitude varies as , so for a given current the field is inversely proportional to the distance from the conductor.

    1 mark

Answer: A. Thumb along current, curled fingers give the direction of the circular field lines; B. Field decreases with distance, B ∝ I/r

Where the marks are

  • Correct statement of the right-hand thumb rule (1 mark)
  • Explains its use: thumb along current, curled fingers show the field direction around the wire (1 mark)
  • States that the field weakens with distance, B ∝ 1/r (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Magnetic Effects of Electric Current, 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.