Automotive Electronics Practice Test

The brushes in a starter motor are used to transfer electrical power between which components?

1. Armature and field coils

2. Commutator segments

3. Field coils and the armature

4. Solenoid and the armature

The correct answer is: Field coils and the armature

The brushes in a starter motor play a crucial role in the operation of the motor by facilitating the transfer of electrical power to the armature. Specifically, they make contact with the commutator segments attached to the armature, enabling the flow of electrical current from the power source to the windings of the armature. This current flow is essential for generating the magnetic field necessary for the motor to operate and start the engine. In this context, the field coils generate the magnetic field that interacts with the armature. The brushes enable the power needed to energize these coils, thus allowing the armature to function effectively within the electromagnetic system of the starter motor. By connecting the electrical supply through the brushes to the moving parts (the armature), the starter motor becomes a functional electric motor capable of cranking the engine. The other answer options do not accurately reflect this function. The brushes do not connect the armature to the field coils directly, nor do they interface with the solenoid in a way that would transfer electrical power. Instead, the brushes are primarily tasked with feeding power to the armature, essential for the starter motor's operation.