Answer
$2.38 \times 10^{22}$ m
Work Step by Step
As per the given problem, we have:
$B=\dfrac{kL}{d^2}$
Here, $k$ is defined as constant of proportionality
Plug the given data in the above expression, we get
$8.2 \times 10^{-16}=(0.080)\dfrac{5.8 \times 10^{30}}{d^2}$
This gives: $d=2.38 \times 10^{22}$ m