Correct Answer - Option 3 : 1.8°

__Concept:__

Step angle of the hybrid stepper motor is given by

\(β = {{(N_s -N_r)× 360°} \over (N_s× N_r)}\)

Where Ns = Number of stator teeth

Nr = Number of rotor teeth

__Calculation:__

Given that, Nr = 50

Ns = 40

∴ stepping angle can be calculated as

\(β = {{(50 -40)× 360°} \over (50× 40)}\)

β = 1.8°