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CUET · PHYSICS · PYQ PAPER 2025

The magnetic field at the centre of a closely wound circular coil of 100 turns, radius 22 cm, carrying a current of 3.5 A will be

  1. A \(1 \times 10^{-2} \, T \)
  2. B \(2 \times 10^{-3} T\)
  3. C \(1 \times 10^{-3} T\)
  4. D \(2 \times 10^{-4} T\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(1 \times 10^{-3} T\)

Step-by-step Solution

Detailed explanation

\(B = \frac{\mu_0 N I}{2r}\) \(B = \frac{(4\pi \times 10^{-7} \text{ T}\cdot\text{m/A}) \times 100 \times 3.5 \text{ A}}{2 \times 0.22 \text{ m}}\) \(B \approx 1 \times 10^{-3} \text{ T}\)