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Assertion (A): On… (Class 12 Physics SQP 2024-25, Q13)

questionbuddy.in/q/cbse-12-physics-2024-25-sqp-q13-increasing-current-sensitivity-galvanometer-increasing

PhysicsCBSE Class 12 · Sample paper, session 2024-25 · 1 mark · Assertion-reason

CBSE Class 12 Physics sample paper 2024-25: question 13

From the official CBSE sample question paper for 2024-25, section A, question 13, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q13 · 1 mark · Assertion-reasonCompetency-basedMoving Charges and Magnetism

Assertion (A): On increasing the current sensitivity of a galvanometer by increasing the number of turns may not necessarily increase its voltage sensitivity.
Reason (R): The resistance of the coil of the galvanometer increases on increasing the number of turns.

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

Source: official sample paper from cbseacademic.nic.in (PDF). See it in the full Sample paper 2024-25.

Hints

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

Hint 1

Write the expressions for both sensitivities.

Hint 2

What else changes when you add turns to the coil?

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. Current sensitivity is and voltage sensitivity is . More turns raise both N and the coil resistance R, so voltage sensitivity may stay the same.

    ½ mark

  2. Both statements are true, and R explains A. The answer is (A).

    ½ mark

Answer: Option (A)

Where the marks are

  • Voltage sensitivity current sensitivity, and R increases with N (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Moving Charges and Magnetism, one at a time, marked against the answer key and marking points.Back to the full paperSample paper 2024-25: 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.