일반물리학 2 — Maxwell's Equations; Magnetism of Matter: Problem 30

30 An electron is placed in a magnetic field \(\vec{B}\) that is directed along a \(z\) axis. The energy difference between parallel and antiparallel alignments of the \(z\) component of the electron’s spin magnetic moment with \(\vec{B}\) is \(4.00 \times 10^{-25} \text{ J}\). What is the magnitude of \(\vec{B}\)?