A current =1 A flоws in the inner cоnductоr of аn infinitely long coаxiаl line and returns via the outer conductor. The radius of the inner conductor is =0.5 mm, and the inner and outer radii of the outer conductor are =1.8 mm and =2 mm, respectively. Find the magnetic flux density (in μT, one decimal point) at a distance r=[x] mm from the center of the inner conductor.