What is the role of ceramic capacitors in DC motors?

A DC motor's electrical noise is a spike in voltage that is mostly produced by the brush, which is caused by the brush being disconnected from the commutator's contact. A DC motor's electrical noise often has a very broad and disorganized pulse signal frequency range. Ceramic capacitors are required to reduce noise and achieve the effect of passing EMC since, in many circumstances, if the proper precautions are not followed, the electrical interference level will exceed the EMC limit.

A extremely low impedance channel to the common terminal of the noise source is what the capacitor does to bypass the voltage spike. It can be linked between two leads or between each of the motor's leads and the ground. A ceramic capacitor inserted between the brush and ground will make a significant difference.