In a Coaxial Cable,the Solid Inner Conductor Carries a Current

Multiple Choice

In a coaxial cable,the solid inner conductor carries a current of I.The shield,which also carries a current of I but in the opposite direction,has an inner radius of a and an outer radius of b.The current density is equally distributed over each conductor.What is the magnitude of at a radial distance of 1.05 mm from the center of the coaxial cable if a = 1 mm,b = 1.1 mm and I = 100 mA?

A) 1.5 mT
B) 10 mT
C) 10 µT
D) 0 T