Automotive Electronics Practice Test

Two light bulbs are wired in series and one bulb burns out. Which technician is correct regarding the state of the other bulb?

1. Technician A

2. Technician B

3. Both Technicians A and B

4. Neither Technician A nor B

The correct answer is: Neither Technician A nor B

In a series circuit, electrical components are connected one after the other, meaning the same current flows through each component. When two light bulbs are wired in series, the circuit is complete as long as both bulbs are functional. If one bulb burns out, it creates an open circuit, breaking the flow of current. As a result, the other bulb will also go out. Since both bulbs depend on the intact connection of the other to complete the circuit, the failure of one directly affects the operation of the other. Therefore, after one bulb burns out, the other bulb cannot power on, and stating otherwise would be incorrect. Technician A or B may have posited that the other bulb could still work, but this is not possible in a series configuration. This understanding leads to the correct conclusion that neither technician accurately describes the situation. This scenario highlights the fundamental principle of series circuits, where continuity is crucial for operation.