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A student fixes a sheet of… (Class 10 Science 2024, Q32)

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ScienceCBSE Class 10 · Board exam 2024, set 31/4/1 · 3 marks · Short answer

CBSE Class 10 Science 2024: question 32

Set in the CBSE Class 10 board exam of 2024, paper 31/4/1, section C, question 32, for 3 marks. Try it first; the hints and our step-by-step solution are below.

Q32 · 3 marks · Short answerMagnetic Effects of Electric Current

A student fixes a sheet of white paper on a drawing board. He places a bar magnet in the centre of it. He sprinkles some iron filings uniformly around the bar magnet. Then he taps the drawing board gently and observes that the iron filings arrange themselves in a particular pattern.
(a) Why do iron filings arrange in a particular pattern ?
(b) What does the crowding of iron filings at the ends of the magnet indicate ?
(c) What do the lines, along which the iron filings align, represent ?
(d) If the student places a cardboard horizontally in a current carrying solenoid and repeats the above activity, in what pattern would the iron filings arrange ? State the conclusion drawn about the magnetic field based on the observed pattern of the lines.

Source: official question paper from cbse.gov.in (PDF). See it in the full 2024 board paper, set 31/4/1.

Hints

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

Hint 1

The iron filings behave like tiny magnets in a field.

Hint 2

Where the field lines are closer together, the field is stronger. What do parallel lines tell you?

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) A magnetic field exists around the bar magnet. It exerts forces on the iron filings, which align along the field.

    ½ mark

  2. (b) The crowding of filings at the ends shows that the magnetic field is strongest near the poles.

    1 mark

  3. (c) The lines represent magnetic field lines.

    ½ mark

  4. (d) Inside the solenoid, the filings arrange in straight, parallel, equally spaced lines.

    ½ mark

  5. Conclusion: the magnetic field inside a current-carrying solenoid is uniform (the same at all points).

    ½ mark

Answer: (a) Magnetic field around the magnet; (b) field is strongest at the poles; (c) magnetic field lines; (d) parallel equidistant straight lines, so the field inside the solenoid is uniform.

Where the marks are

  • (a) Due to the magnetic field of the magnet (½ mark)
  • (b) Field is strongest at the poles (1 mark)
  • (c) Magnetic field lines (½ mark)
  • (d) Parallel straight lines (½ mark); field is uniform (½ 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 paper2024 board paper, set 31/4/1: 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.