Magnetic Field Calculation

The magnetic field (B) at a distance r from a long straight wire carrying current I is given by:

B = (μ₀ I) / (2π r)

B = (4π×10⁻⁷ × 50) / (2π × 2.5) = 4.0 × 10⁻⁶ T

Where:
μ₀ = permeability of free space (4π×10⁻⁷ T·m/A)
I = current (50 A)
r = distance from wire (2.5 m)

The direction is determined by the right-hand rule: Point your thumb in the current direction, and your fingers curl in the field direction. At a point east of the wire, the field points vertically upward for north-to-south current.