A three- phase, three-stack variable reluctance stepper motor has 20 poles on each rotor and stator stack. The step angle of this motor is

A three- phase, three-stack variable reluctance stepper motor has 20 poles on each rotor and stator stack. The step angle of this motor is   (GATE-EE-2007)

A. 3
B. 6
C. 9
D. 18


EXPLANATORY ANSWER:

Step angle= 360/ m*Nr

where
Nr=no.of rotor poles

m=no.of phases

therefore   step angle=360/3*20

step angle=6