Question

Janelle wants to buy some strings of decorative lights for her home. She is trying to decide between two strings of lights that are wired differently.

How should Janelle’s lights be wired, and why?

Answer 1

She should wire the lights in parallel.

Why:
- In parallel each bulb (or short string) is connected directly across the supply, so every bulb gets the full source voltage and its brightness does not depend on how many other bulbs are lit.
- If one bulb burns out or is removed, the other bulbs stay lit because each has its own path to the supply.
- In contrast, in a series string the same current flows through every bulb. One open bulb breaks the circuit and turns the whole string off, and adding more bulbs reduces the voltage and brightness of each bulb.

(Practical note: parallel wiring draws more total current than a comparable series string, so bulbs should be chosen/rated for the mains voltage and the string installed on a circuit sized for the load; modern decorative strings often combine techniques and include shunts or fuses.)