In an electrical circuit, which action completes the circuit when the dome light should come on?

In an electrical circuit, which action completes the circuit when the dome light should come on?

• A. Breaks the circuit
• B. Completes the circuit
• C. Grounds the circuit
• D. Short circuits

Answer: (B)

A circuit must be closed for current to flow; completing the circuit allows the dome light to illuminate. In a car, the dome light is powered from the battery and the door switch provides a path to return current. When the door is opened, the switch closes and completes the path back to the battery ground, letting current flow through the lamp and turn it on. If the circuit is broken, no current can flow and the light stays off. Grounding is part of the return path, but the action that turns the light on is the completion of the circuit. Short circuits are faults that create excessive current, not the normal operation.

A circuit must be closed for current to flow; completing the circuit allows the dome light to illuminate.

In a car, the dome light is powered from the battery and the door switch provides a path to return current. When the door is opened, the switch closes and completes the path back to the battery ground, letting current flow through the lamp and turn it on. If the circuit is broken, no current can flow and the light stays off. Grounding is part of the return path, but the action that turns the light on is the completion of the circuit. Short circuits are faults that create excessive current, not the normal operation.