Correct option is A
Multi-Stack Variable Reluctance Stepper Motors:
These motors use multiple stacks of rotor and stator sections to achieve smaller step sizes and higher resolution.
The multiple stacks create a finer pitch between the rotor and stator teeth, resulting in smaller angular displacements per step.
The step sizes for multi-stack variable reluctance stepper motors are typically in the range of 2° to 15°.
A Multi Stack or m stack variable reluctance stepper motor is made up of m identical single stack variable reluctance motor.
The rotor is mounted on a single shaft. The stator and rotor of the Multi Stack Variable motor have the same number of poles and hence, the same pole pitch.
All the stator poles are aligned in a multi-stack motor. But the rotor poles are displaced by 1/m of the pole pitch angle from each other.
The stator windings of each stack form one phase as the stator pole windings are excited simultaneously. Thus, the number of phases and the number of stacks are the same.
