Determine the instantaneous torque experienced by the loop below when it is placed in a uniform magnetic field $\boldsymbol{B}$, whose direction is depicted in the figure. The loop is composed of two semicircles of radius $r$ that subtend a right angle. $\boldsymbol{B}$ bisects the angle between the semicircles.
In light of the previous set-up, propose a definition for the magnetic dipole moment $\boldsymbol{\mu}$ of a non-planar loop C with $N$ turns, carrying a current $I$, such that the torque that it experiences in a uniform magnetic field $\boldsymbol{B}$ is
$$
\tau=\mu \times B
$$
(GRAPH CAN'T COPY)