The figure below shows a $90-$turn square coil rotating about a vertical axis at at $=1,320re\frac{v}{m}in.$ The length of a side of the coil is $20\mathrm{.}0$ cm $.$ The horizontal component of the Earth's magnetic field at the coil's location is equal to $2\mathrm{.}00{10}^{-5}T.$

$($a$)$ What is the magnitude of the maximum emf $($in mV $)$ induced in the coil by the Earth's magnetic field?

$mV$

$($b$)$ What is the orientation of the coil with respect to the magnetic field when the maximum emf occurs?

The plane of the coil is perpendicular to the magnetic field.

The plane of the coil is oriented $45$ with respect to the magnetic field.

The plane of the coil is parallel to the magnetic field.