Light bulbs changed how people live, and they are still a great topic for riddles. This collection covers the lights around your home, the inventors behind the bulb and the science of watts, lumens and LEDs.
Every riddle has its own answer, and the brain teaser section includes the classic three-switch puzzle that has stumped people for decades.
Easy Light Riddles for Kids
- I glow when you switch me on, and you screw me into a lamp. What am I? 👉 A light bulb
- I am on the wall, and you flip me to turn the lights on and off. What am I? 👉 A light switch
- I sit on your desk with a shade and a bulb to help you read. What am I? 👉 A lamp
- I am the thin wire inside an old-style bulb that glows bright. What am I? 👉 The filament
- I flow through wires and make the bulb light up. What am I? 👉 Electricity
- I am a small light you hold in your hand, and I run on batteries. What am I? 👉 A flashlight
- I cover a bulb to make its light softer. What am I? 👉 A lampshade
- In cartoons, a glowing bulb above someone’s head means they just had me. What am I? 👉 A bright idea
- I am a fancy light that hangs from the ceiling, covered in sparkling crystals. What am I? 👉 A chandelier
- I have three colored lights and I tell cars when to stop and go. What am I? 👉 A traffic light
- I am a tall tower by the sea with a powerful light that warns ships. What am I? 👉 A lighthouse
- I am a long string of tiny bulbs that people hang up at holidays. What am I? 👉 Fairy lights
Light Bulb Science Riddles
These riddles are based on real science and history. The note after each answer explains it.
- My company made the first practical, long-lasting light bulbs in 1879. Who am I? 👉 Thomas Edison
- I am a British inventor who showed a working light bulb at around the same time as Edison. Who am I? 👉 Joseph Swan
- Old bulb filaments are made of me, a metal that can get extremely hot without melting. What am I? 👉 Tungsten
- I am an energy-saving bulb made with tiny semiconductors. What am I? 👉 An LED
- LED is short for these three words. What are they? 👉 Light-emitting diode
- Old-style bulbs turn about 90 percent of their energy into this instead of light. What is it? 👉 Heat
- I am the unit of power printed on bulbs, like 40 or 60. What am I? 👉 Watts
- I am the unit that tells you how much light a bulb actually gives off. What am I? 👉 Lumens
- I am a bulb in a California fire station that has been glowing almost nonstop since 1901. What am I? 👉 The Centennial Light
- Many old bulbs were filled with me, an unreactive gas that helps the filament last longer. What am I? 👉 Argon
- I describe whether light looks warm and yellow or cool and blue, and I am measured in kelvin. What am I? 👉 Color temperature
Funny Light Bulb Riddles
- Why did the light bulb fail its test? 👉 It was not very bright
- What do you call a light bulb that is always happy? 👉 Delighted
Light Bulb Brain Teasers
- Three switches outside a closed room control one bulb inside. You can open the door only once. How do you find the right switch? 👉 Turn on switch 1 for a few minutes, turn it off, turn on switch 2 and go in (if the bulb is on it is switch 2, warm and off is switch 1, cold and off is switch 3)
- A 10-watt LED is on for 5 hours a day for 10 days. How many watt-hours does it use? 👉 500
- A room has 3 lamps with 2 bulbs each, and one bulb burns out. How many bulbs still work? 👉 5
- Which gives more light: an old 60-watt bulb or an LED rated at 800 lumens? 👉 About the same
Want more riddles? Browse our blog for more collections, and if you spot a mistake in any answer, let us know on our Contact page.