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In a coil of resistance… (Class 12 Physics SQP 2023-24, Q11)

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PhysicsCBSE Class 12 · Sample paper, session 2023-24 · 1 mark · MCQ

CBSE Class 12 Physics sample paper 2023-24: question 11

From the official CBSE sample question paper for 2023-24, section A, question 11, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q11 · 1 mark · MCQElectromagnetic Induction

In a coil of resistance 100 a current is induced by changing the magnetic flux through it. The variation of current with time is as shown in the figure. The magnitude of change in flux through coil is

  1. (A)200 Wb
  2. (B)275 Wb
  3. (C)225 Wb
  4. (D)250 Wb

Figure in the paper: Graph of current I (vertical axis) versus time t (horizontal axis): a straight line falling from I = 10 A at t = 0 to zero at t = 0.5 s. See it in the official paper.

Source: official sample paper from cbseacademic.nic.in (PDF). See it in the full Sample paper 2023-24.

Hints

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

Hint 1

Relate induced emf to rate of change of flux and to IR.

Hint 2

Charge flowing equals the area under the I–t graph.

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. (area under I–t graph).

    ½ mark

  2. Area C, so Wb.

    ½ mark

Answer: 250 Wb, option (D)

Where the marks are

  • Δφ = R × area under I–t graph (½ mark)
  • Computes 250 Wb (½ mark)

Revise the chapter

Practise this chapterBoard-style questions from Electromagnetic Induction, one at a time, marked against the answer key and marking points.Back to the full paperSample paper 2023-24: 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.