A straight conductor carries 20 A along the y-axis. The magnetic field at (0.3 m, 0, 0.4 m) is (μ₀ = 4π × 10⁻⁷ T·m/A):
Correct answer: B. 8 × 10⁻⁶ T
- A. 4 × 10⁻⁶ T
- B. 8 × 10⁻⁶ T
- C. 12 × 10⁻⁶ T
- D. 16 × 10⁻⁶ T
Explanation
Distance r = √(0.3² + 0.4²) = 0.5 m. Magnetic field B = (μ₀I)/(2πr) = (4π × 10⁻⁷ × 20)/(2π × 0.5) = 8 × 10⁻⁶ T. Direction is determined by the right-hand rule.
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Magnetic flux density and magnetic flux describe the strength of a magnetic field and the field passing through a surface. A charged particle moving through a magnetic field experiences a force perpendicular to its velocity and may follow circular or helical motion, depending on the angle between velocity and field.
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