일반물리학 2 — Magnetic Fields: Problem 23

23 A wire of length $12.5\text{ cm}$ carrying a current of $2.33\text{ mA}$ is to be formed into a circular coil and placed in a uniform magnetic field of magnitude $5.71\text{ mT}$. If the torque on the coil from the field is maximized, what are (a) the angle between $\vec{B}$ and the coil’s magnetic dipole moment and (b) the number of turns in the coil? (c) What is the magnitude of that maximum torque?