If the two supply wires to a DC series motor are reversed, what will happen to the motor's direction?

When the supply wires to a DC series motor are reversed, the direction of the current flowing through the armature and the field windings is also reversed. However, since both the armature and field windings are connected in series, reversing the supply leads does not change the relative directions of the magnetic field and the armature current. As a result, the torque produced in the motor remains in the same direction, meaning the motor will continue to rotate in its original direction.

To elaborate, in a series motor, the field current is directly influenced by the armature current. When the supply is reversed, both the field and armature current directions change, but because of their series connection, the operational dynamics remain unaffected. The forces that drive the motor continue to act in the same directional context. Thus, the motor will continue to run in its original direction despite the reversal of the supply wires.

This is why the answer indicates that the motor will run in the same direction instead of stopping or running in the opposite direction. Additionally, reversing the wires does not inherently lead to overheating, as overheating would typically result from excessive load or poor connections, rather than the simple act of reversing supply leads.