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The following activity… (Class 10 Science SQP 2025-26, Q25)

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ScienceCBSE Class 10 · Sample paper, session 2025-26 · 2 marks · Very short answer

CBSE Class 10 Science sample paper 2025-26: question 25

From the official CBSE sample question paper for 2025-26, section B, question 25, for 2 marks. Try it first; the hints and our step-by-step solution are below.

Q25 · 2 marks · Very short answerCompetency-basedMetals and Non-metals

The following activity is set-up in the science lab by the teacher. He clamped an aluminium wire on a stand and fixed a pin to the free end of the wire using wax. Then he heated the wire with a burner from the end where the wire is clamped. Students observed the pin fall off.
A. If the teacher replaces aluminium wire by silver wire, will the students' observation change? Justify your answer.
B. Will the aluminium wire melt? Give reason for your answer.

Figure in the paper: A stand with a clamp holds a horizontal metal wire at one end. A pin is attached with wax to the free end of the wire. A spirit lamp with flame is placed below the wire near the clamped end. Labels: Stand, Clamp, Metal wire, Free end of wire, Pin, Wax, spirit lamp. See it in the official paper.

Source: official sample paper from cbseacademic.nic.in (PDF). See it in the full Sample paper 2025-26.

Hints

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

Hint 1

What property of the wire makes the wax melt?

Hint 2

Compare silver and aluminium as heat conductors. Then compare the melting points of wax and a metal.

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 pin falls because heat is conducted along the wire and melts the wax at the free end.

  2. With a silver wire the pin will still fall, but sooner. Silver is a better conductor of heat than aluminium, so the wax melts faster.

    1 mark

  3. B. No, the aluminium wire will not melt. Metals such as aluminium have high melting points (about 660 °C for Al). The flame only heats the wire enough to melt the wax, which has a low melting point.

    1 mark

Answer: A. Pin still falls but in less time, since silver conducts heat better. B. No, aluminium has a high melting point.

Where the marks are

  • States the pin falls sooner with silver because silver is a better heat conductor (1 mark)
  • States aluminium will not melt because of its high melting point (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Metals and Non-metals, one at a time, marked against the answer key and marking points.Back to the full paperSample paper 2025-26: 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.