Final answer:
The minimum static flux density exists in the magnetic circuit when the rotating magnet is at a minimum angle with respect to the magnetic field.
Step-by-step explanation:
The minimum static flux density exists in the magnetic circuit when the rotating magnet is at a minimum angle with respect to the magnetic field.
This means that the magnetic flux through the circuit is minimized when the magnet is aligned in a way that maximizes the angle between the magnet and the magnetic field.