A Wire of Radius R = 1

Multiple Choice

A wire of radius R = 1.5 mm and carries a current.The current density is given by the function J = J₀ (1 - r/R) where r is measured from the center of the wire and J₀ = 1.06 * 10⁵ A/m².Use Ampère's law to find the magnetic field at the surface of the wire.What is the magnitude of B if I = 1A,R = 1.5 mm.

A) 148 µT
B) 12 µT
C) 100 µT
D) 33 µT
E) 37 µT