A coil has N sub a turns enclosing an area of A. In a physics laboratory experiment, the coil is rotated during the time interval change in t from a position in which the plane of each turn is perpendicular to Earth's magnetic field to one in which the plane of each turn is parallel to the field. The magnitude of Earth's magnetic field at the lab location is B.
What is the total magnitude I initial of the magnetic flux through the coil before it is rotated?
What is the magnitude of the average emf induced in the coil?