Why was the blue LED such a big deal?

It made bright white LED lighting possible

How do many white LEDs make their light?

A blue LED shines through a yellow phosphor

LED Bulb Quiz: Efficiency, Lumens and Blue LED History

This LED bulb quiz switches on the science of the lights that replaced old incandescent bulbs. Play an interactive set of 10 questions on light-emitting diodes, Nick Holonyak's red LED, the blue LED and its Nobel Prize, making white light with phosphor, lumens versus watts, color temperature, lifespan and heat.

Start LED Bulb Quiz

🎯 Daily Trivia Challenge • 🧠 10 Questions • ⏱️ 150 Seconds

Question 1 / 10 Time: 150s

Stand
What does LED stand for?
First
Who made the first practical visible LED in 1962?
Blue
Why was the blue LED such a big deal?
Nobel
When did the blue LED inventors win the Nobel Prize in Physics?
White
How do many white LEDs make their light?
Save
Roughly how much less energy do LEDs use than incandescent bulbs?
Lumens
What do lumens measure?
Equal
About how many lumens match an old 60-watt bulb?
Kelvin
What does a 2700K rating describe?
Life
How long can a good LED bulb last?

Explanations: answer key for all 10 questions

Q1: What does LED stand for?
Answer: Light-emitting diode
It is a semiconductor.
Q2: Who made the first practical visible LED in 1962?
Answer: Nick Holonyak
It glowed red.
Q3: Why was the blue LED such a big deal?
Answer: It made bright white LED lighting possible
It was very hard to make.
Q4: When did the blue LED inventors win the Nobel Prize in Physics?
Answer: 2014
Akasaki, Amano and Nakamura shared it.
Q5: How do many white LEDs make their light?
Answer: A blue LED shines through a yellow phosphor
The colors combine to look white.
Q6: Roughly how much less energy do LEDs use than incandescent bulbs?
Answer: About 75 to 90 percent less
Little energy is wasted as heat.
Q7: What do lumens measure?
Answer: Brightness
Watts measure energy use.
Q8: About how many lumens match an old 60-watt bulb?
Answer: About 800
Check the box for lumens.
Q9: What does a 2700K rating describe?
Answer: A warm, yellowish white light
Higher numbers look cooler.
Q10: How long can a good LED bulb last?
Answer: Tens of thousands of hours
Far longer than old bulbs.

Led Bulb Quiz – Efficiency, Lumens and Blue LED History

LED stands for light-emitting diode, a semiconductor that glows when current flows through it. Nick Holonyak made the first practical visible LED, a red one, in 1962.

Bright blue LEDs were very hard to make until Isamu Akasaki, Hiroshi Amano and Shuji Nakamura succeeded, winning the 2014 Nobel Prize in Physics. Many white LEDs shine blue light through a yellow phosphor.

LED bulbs use about 75 to 90 percent less energy than incandescent bulbs and last tens of thousands of hours. Shoppers compare lumens for brightness, about 800 for an old 60-watt bulb, and Kelvin ratings for warm or cool light.

What This Quiz Teaches

Tech fans will enjoy these questions.

What LEDs are
Who invented them
Why blue LEDs mattered
How to read bulb labels
How much energy they save

Did You Know?

LEDs turn on instantly at full brightness.
They give off much less heat than old bulbs.
Smart LED bulbs can change color by app.
LEDs light screens, traffic lights and car lamps.
Many countries phased out incandescent bulbs.