Answer
$B=2.0 \times 10^{-2} \mathrm{~T} \text {. }$
Work Step by Step
$$
\text { Using Formula }\\ B=\frac{\mu_0}{2 \pi} \frac{\mu_p}{r^3}\\=\frac{\left(4 \pi \times 10^{-7} \mathrm{~T} \cdot \mathrm{m} / \mathrm{A}\right)\left(1.4 \times 10^{-26} \mathrm{~J} / \mathrm{T}\right)}{2 \pi\left(5.2 \times 10^{-11} \mathrm{~m}\right)^3}\\=2.0 \times 10^{-2} \mathrm{~T} \text {. }
$$
