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Answer the following. (Class 10 Science 2024, Q32)

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ScienceCBSE Class 10 · Board exam 2024, set 31/5/1 · 3 marks · Short answer

CBSE Class 10 Science 2024: question 32

Set in the CBSE Class 10 board exam of 2024, paper 31/5/1, 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

Answer the following.

  1. (a)

    What happens when a bundle of wires of soft iron is placed inside the coil of a solenoid carrying a steady current? Name the device obtained. Why is it called so?

    1 mark
  2. (b)

    Draw the magnetic field lines inside a current carrying solenoid. What does this pattern of magnetic field lines indicate?

    2 marks

Source: official question paper from cbse.gov.in (PDF). See it in the full 2024 board paper, set 31/5/1.

Hints

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

Hint 1

A current-carrying solenoid behaves like a bar magnet. What happens to a magnetic material placed inside it?

Hint 2

Soft iron loses its magnetism quickly. For the field lines inside, think about their spacing and direction, and what equal spacing means.

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) The soft iron bundle gets strongly magnetised by the magnetic field of the current-carrying solenoid.

    ½ mark

  2. The device obtained is an electromagnet.

    ½ mark

  3. It is called so because it behaves as a magnet only as long as current flows through the solenoid; it loses its magnetism when the current is switched off.

    ½ mark

  4. (b) Diagram (described): draw a solenoid connected to a cell and key. Inside the coil draw several straight, parallel, equally spaced field lines along the axis with arrows from the S end to the N end. Outside, the lines curve from the N end back round to the S end, like a bar magnet's field. Mark N and S and the direction of current.

    1 mark

  5. The straight, parallel, equally spaced lines indicate that the magnetic field inside the solenoid is uniform (same strength and direction at all points).

    ½ mark

Answer: (a) It gets magnetised to form an electromagnet, so called because it is a magnet only while current flows. (b) Parallel straight lines inside the solenoid show a uniform magnetic field.

Where the marks are

  • States that the soft iron gets magnetised (½ mark)
  • Names the electromagnet (½ mark)
  • Gives the reason: it is a magnet only while current flows (½ mark)
  • Draws parallel field lines inside the solenoid with direction (1 mark)
  • States that the field inside 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 31/5/1: 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.