National League for Nursing (NLN) Science Practice Exam

What type of connection allows remaining light bulbs to stay lit when one burns out?

1. Series

2. Parallel

3. Short circuit

4. A 220-volt line

The correct answer is: Parallel

A parallel connection allows the remaining light bulbs to stay lit even if one bulb burns out because each bulb is connected independently across the power source. In a parallel circuit, there are multiple paths for electricity to flow. When one bulb fails, it breaks the circuit only for that specific bulb, but the other bulbs continue to receive electrical current because they are on separate pathways. This characteristic is crucial for maintaining the functionality of multiple components in a circuit as it enhances reliability. In contrast, a series connection would mean that the light bulbs are connected in a single path, and when one bulb burns out, it breaks the entire circuit, causing all bulbs to go out. A short circuit represents a fault condition where the current bypasses the normal load, often leading to circuit failure, while a 220-volt line refers to the voltage supply and doesn't directly pertain to the functionality of connections between bulbs. Therefore, the parallel connection is the correct answer in maintaining the operation of other bulbs even when one fails.