46. How can the direction of rotation of a DC motor be reversed?

Reversing either the field or armature connections reverses the DC motor's rotation. This is because the motor's direction of rotation depends on the interaction between the magnetic field and the armature current; reversing one changes this interaction and thus the direction of rotation. Reversing both connections cancels the effect and maintains the original rotation direction, while series or parallel wiring only affects motor characteristics, not rotation direction.