The same source parameter gives weaker field as radius-square grows. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Radius 1 gives field 16
The source parameter stays 16. Radius 1 has square 1, so the field is 16.
g=r2μ=116=16
Radius 2 gives field 4
The source parameter stays 16. Radius 2 has square 4, so the field is 4.
g=r2μ=416=4
Radius 4 gives field 1
The source parameter stays 16. Radius 4 has square 16, so the field is 1.
g=r2μ=1616=1
Field strength follows the inverse-square denominator
With the same source parameter, radius one, two, and four make radius-squares one, four, and sixteen. The field steps down as sixteen, four, and one.