Question 446Electricity & Electronics - Assistant Engineer

The correct answer is B) A partial short circuit. If dirt and grease are allowed to accumulate between the commutator segments of a DC motor, it can lead to a partial short circuit. This occurs because the dirt and grease can create a conductive path between adjacent commutator segments, causing a portion of the windings to be shorted out. This partial short circuit can reduce the motor's efficiency and lead to increased heating and potential damage to the motor. The other options are incorrect because: A) Misalignment of the motor shaft is not a direct consequence of commutator segment contamination, C) A dead short circuit would require a complete connection between all commutator segments, and D) Overspeeding of the motor is not a typical outcome of commutator segment contamination.