A 0.1 m radius loop carries 5 A. The magnetic field at a point on its …

Question

A 0.1 m radius loop carries 5 A. The magnetic field at a point on its axis 0.1 m from the centre is approximately (μ₀ = 4π × 10⁻⁷ T·m/A)

Accepted Answer

D. 1.1 × 10⁻⁵ T

1. Use B = μ₀IR² / (2(R²+x²)^(3/2)).
2. With R = x = 0.1 m: R²+x² = 0.02 m²; (0.02)^(3/2) ≈ 0.002828.
3. Numerator: μ₀IR² = 4π × 10⁻⁷ × 5 × 0.01 ≈ 6.28 × 10⁻⁸.
4. B = 6.28 × 10⁻⁸ / (2 × 0.002828) ≈ 1.11 × 10⁻⁵ T.
_Source: NCERT Class 12 Physics Ch 4 "Moving Charges and Magnetism", §4.6_

Answer

1.6 × 10⁻⁵ T

Answer

2.2 × 10⁻⁵ T

Answer

3.1 × 10⁻⁵ T