Recall the Biot-Savart law for the magnetic field B created by a moving point charge:
B = μ₀/4π * qv×r/|r|³
μ₀ is the vacuum permeability (4π×10⁻7 H/m), q is the charge, v is the velocity vector, r is the position vector from the point charge to the point in space where you are measuring the B field, and |r| is the magnitude of the position vector.
