Answer: B, 0.75°
The rotor teeth of the four-phase reaction stepper motor is 60, and the step angle is 0.75°.
Stepper motor is a digital motor whose number of rotor teeth is related to the number of stator poles. In the four-phase reaction stepper motor, the common number of stator poles is 2, 3, 4, 5, 6, 8, 12, etc., of which the motor with a power of 2 pole has high torque and accuracy. Therefore, according to the number of rotor teeth of 60, the number of poles to the power of 2 of the stator pole can be calculated, that is, 12.
Since the number of stator poles is 12, the motor rotor needs to pass through 12 electrical angles per revolution, that is, 360° electric angle / 12=30° electric angle. The step angle refers to the angle of rotation of the rotor at each step, so the step angle is 30° electric angle / 60 teeth = 0.5° electric angle.
Therefore, the step angle of this stepper motor is 0.75° (half of the 0.5° electric angle), option B is correct.