The loop in the figure is rotated by an angle $=300$ and the current flowing into the

loop is $4\mathrm{.}5$ A$.$ The side a is $0\mathrm{.}38$ m long, and side b is $0\mathrm{.}15$ m long.

$($a$)$ What is the magnitude of the magnetic dipole moment?

$($b$)$ If the torque applied to the loop by the magnetic field is $0\mathrm{.}9$ N m$,$ what is the

magnitude of the magnetic field?