Skip to content

Assertion (A): Nichrome is an… (Class 10 Science 2025, Q19)

questionbuddy.in/q/cbse-10-science-2025-31-2-1-q19-nichrome-alloy-commonly-used-electrical

ScienceCBSE Class 10 · Board exam 2025, set 31/2/1 · 1 mark · Assertion-reason

CBSE Class 10 Science 2025: question 19

Set in the CBSE Class 10 board exam of 2025, paper 31/2/1, section A, question 19, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q19 · 1 mark · Assertion-reasonCompetency-basedElectricity

Assertion (A): Nichrome is an alloy which is commonly used in electrical heating devices such as electric irons, toasters, etc.

Reason (R): The resistivity of nichrome is high and its resistance decreases with increase in temperature.

  1. (A)Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
  2. (B)Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
  3. (C)Assertion (A) is true, but Reason (R) is false.
  4. (D)Assertion (A) is false, but Reason (R) is true.

Source: official question paper from cbse.gov.in (PDF). See it in the full 2025 board paper, set 31/2/1.

Hints

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

Hint 1

Check each part of R separately.

Hint 2

Does the resistance of a metal alloy fall when it gets hot?

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. Nichrome is used in the heating elements of irons, toasters and similar devices. A is true.

  2. Nichrome does have a high resistivity, but its resistance does not decrease when it is heated. It also does not oxidise easily at high temperatures. So R is false.

  3. Answer: (C).

    1 mark

Answer: (C)

Where the marks are

  • A true, R false (resistance does not decrease on heating), option (C) (1 mark)

Revise the chapter

  • Chapter: Electricity (notes, formulas, where marks are lost and every past question)
Practise this chapterBoard-style questions from Electricity, one at a time, marked against the answer key and marking points.Back to the full paper2025 board paper, set 31/2/1: 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.