What is the function of motor brushes in a DC motor?

The function of motor brushes in a DC motor is to connect the negative or positive line to the commutator segments. The brushes are typically made of conductive material and they maintain electrical contact with the rotating commutator, allowing current to flow into the armature windings. This flow of current is crucial because it generates the electromagnetic field needed to create motion in the rotor.

In a DC motor, the commutation process relies on the brushes to switch the direction of the current in the armature windings as the rotor turns, ensuring that the torque generated is constant and that the motor continues to rotate in one direction. This process directly involves the brushes, which effectively complete the circuit by transferring electrical energy from the stationary part of the motor (the stator) to the rotating part (the rotor).

The other options, while they refer to components and functions associated with a motor, do not accurately describe the specific role of motor brushes in a DC motor, which is primarily focused on transferring electrical energy needed for operation and commutation.