Skip to content

An electric iron rated 2·2… (Class 12 Physics 2026, Q17a)

questionbuddy.in/q/cbse-12-physics-2026-55-5-1-q17a-electric-iron-rated-operated-supply

PhysicsCBSE Class 12 · Board exam 2026, set 55/5/1 · 2 marks · Very short answer

CBSE Class 12 Physics 2026: question 17(a)

Set in the CBSE Class 12 board exam of 2026, paper 55/5/1, section B, question 17(a), for 2 marks. Try it first; the hints and our step-by-step solution are below.

Q17(a) · 2 marks · Very short answerCurrent Electricity

An electric iron rated 2·2 kW, 220 V is operated at 110 V supply. Find :
(i) its resistance, and
(ii) heat produced by it in 10 minutes.

Source: official question paper from cbse.gov.in (PDF). See it in the full 2026 board paper, set 55/5/1.

Hints

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

Hint 1

The resistance of the iron does not change when the supply voltage changes.

Hint 2

Find R from the rated values, then use at 110 V.

Hint 3

Heat = power × time, with time in seconds.

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. (i) The resistance is fixed by the rating:

    1 mark

  2. (ii) At 110 V the resistance is still 22 Ω, so W.

    Heat in min s: J

    1 mark

Answer: (i) 22 Ω; (ii) 3.3 × 10^5 J

Where the marks are

  • Uses to get 22 Ω (1 mark)
  • Finds power 550 W at 110 V and heat J in 600 s (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Current Electricity, one at a time, marked against the answer key and marking points.Back to the full paper2026 board paper, set 55/5/1: 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.