Christmas Lights Quiz
Welcome to the Christmas Lights Quiz, reviewed for 2026.
These 18 questions move from everyday light and safety knowledge to circuits, color temperature, LEDs, and the documented history of electric Christmas trees.
After the quiz, plan a Christmas lights walk and photography project, visit National Christmas Lights Day, or explore the Christmas hub.
Challenge note: The hard round is designed to be difficult. Take your time, use the hints, and read each explanation before moving on.
Question 1:
What does LED stand for?
The final word is diode.
Light-emitting diode - An LED is a light-emitting diode: a semiconductor device that releases visible light when current passes through it.
Question 2:
Before using an old string of lights, what should you check first?
Look for physical damage.
Sockets, wires, connections, and bulbs for damage - CPSC advises inspecting new and old sets for cracked sockets, frayed or bare wires, loose connections, and missing bulbs.
Question 3:
When should decorative tree lights be turned off?
Think unattended lights.
When leaving home or going to bed - CPSC safety guidance says to turn lights off when leaving the house or going to bed.
Question 4:
Which lights should be used outside?
Read the use rating.
Lights specifically rated for outdoor use - Outdoor products and cords must be intended for outdoor conditions; follow the product label and instructions.
Question 5:
What unit is commonly used for lamp color temperature?
It is a temperature unit.
Kelvin - Lamp color temperature is commonly expressed in kelvins, written K.
Question 6:
Which light usually looks warmer?
Warm appearance uses the lower number.
A lower color-temperature light - Lower color temperatures are generally described as warmer or more yellow, while higher values appear cooler or bluer.
Question 7:
What happens in a simple series circuit if one bulb creates an open circuit?
The electrical path is no longer complete.
Current stops through that series - An open circuit breaks the path, so current cannot flow through that series of bulbs.
Question 8:
In a parallel circuit, what can happen when one lamp fails?
Each branch has its own path.
Other branches can remain lit - Parallel branches have separate paths to the power source, so one failed branch need not interrupt the others.
Question 9:
Why is a fuse used in many holiday-light plugs?
It is a protective weak link.
To interrupt excessive current before wiring overheats - A fuse is overcurrent protection designed to open the circuit before excessive current overheats the strand.
Question 10:
Compared with conventional incandescent strands, LED holiday lights generally use what kind of component to make light?
The clue is in the D of LED.
A semiconductor diode - LEDs use semiconductor junctions rather than heating a filament until it glows.
Question 11:
What kind of fastener should not pierce an electrical light cord?
Avoid anything sharp through the wire.
Nails or tacks - CPSC guidance warns against nails or tacks because piercing or damaging insulation can create shock or fire hazards.
Question 12:
What should you do with a strand that has frayed or bare wires?
Visible wire damage is a stop signal.
Stop using it and follow safe repair or disposal guidance - Damaged insulation can expose live conductors and create shock or fire risk; do not energize a damaged set.
Question 13:
Who displayed the first electrically lit Christmas tree known to Smithsonian historians in 1882?
He worked with Edison.
Edward Johnson - Smithsonian historians identify Edward Johnson, an associate of Thomas Edison, with the known 1882 electrically lit Christmas tree.
Question 14:
Which three bulb colors did Smithsonian historians describe on Edward Johnson’s 1882 tree?
They match three colors of the United States flag.
Red, white, and blue - The National Museum of American History describes the early electrically lit tree as using red, white, and blue bulbs.
Question 15:
Why do many modern holiday strands combine series and parallel wiring?
Think groups of bulbs.
A failed series can be isolated while other series keep a path - Parallel groups can keep operating when another series branch is open, while bulbs within a group share a series path.
Question 16:
In a traditional incandescent miniature bulb, what normally produces visible light?
It is a very hot wire.
A hot filament - Electric current heats a thin filament until it glows, converting much of the input energy into heat.
Question 17:
What approximate color temperature does NIST give for an old-fashioned yellowish incandescent lamp?
It is in the low thousands.
About 3,000 K - NIST uses about 3,000 K as an everyday example of the yellowish color temperature of an old-fashioned incandescent lamp.
Question 18:
Which safety features does CPSC identify for seasonal decorative lighting products?
They protect the wiring and connection points.
Minimum wire size, strain relief, and overcurrent protection - CPSC identifies minimum wire size, sufficient strain relief, and overcurrent protection as observable safety characteristics.
