The magnetic moment of a current carrying loop is 2.1  ×  10−25  Am2.  The magnetic field at a point on its axis at a distance of 1Ao is

Field at a point x from the centre of a current carrying loop on the axis isB  =  μ04π.2Mx3= 10−7 ×  2 × 2.1 × 10−2510−103 =4.2 × 10−32 × 1030= 4.2 × 10−2  Wb/m2