Quiz: How does a light bulb work?
What's inside a light bulb? Why don't they burst into flames? What exactly makes a light bulb glow, anyway? Take our quiz to see whether you're in the dark about how light bulbs work.
What was a drawback to using oil lamps for lighting?
- Lamp oil leaves a sooty residue on walls.
- Lamp oil is smelly.
- Lamp oil is expensive.
Who was the first to invent an affordable and workable electric light for the home?
- Sir Joseph Swan
- Thomas Edison
- Guglielmo Marconi
When was the light bulb invented?
- the 1850s
- the 1870s
- the 1910s
Twenty-five years after its invention, how many homes around the world had light bulbs?
- about 250,000
- about 500,000
What are light particles called?
Which of these weighs the least?
When an electron has more energy, will it be closer, farther or the same distance from the nucleus of the atom?
- the same distance
What causes light to be a specific color?
- the type of atom releasing the light
- the amount of energy that excites the atom
- the number of neutrons in the atom
How many contacts are on the base of an incandescent light bulb?
What is a free electron?
- an electron not attached to an atom
- an electron with no charge
- an electron in an orbit that's far from the nucleus
In an electrical current, in what direction do the electrons flow?
- from negative charge to positive
- from positive charge to negative
- from charged to uncharged
How does electrical current excite the atoms as it flows through a bulb's filament?
- They heat the atoms by bumping into them.
- They bond with the atoms, increasing their mass.
- They temporarily pass through and split the atoms.
Why is a thinner filament better for lighting than a thicker one?
- Electrons have a harder time moving through a thinner filament.
- Thinner filaments are easier to fit into bulbs.
- Thicker filaments wear out more easily.
How hot does the filament of a light bulb get?
- 1,500 degrees Fahrenheit (815 degrees Celsius)
- 4,000 degrees Fahrenheit (2,204 degrees Celsius)
- 6,000 degrees Fahrenheit (3,315 degrees Celsius)
If you stretched out the filament in a 60-watt bulb, how long would it be?
- 2 feet (0.61 meters)
- 4 feet (1.2 meters)
- 6.5 feet (1.9 meters)
Why is tungsten a good metal to use for light bulb filaments?
- its high melting point
- its low cost
- its flexibility
Why did manufacturers stop sucking the air out of the insides of light bulbs?
- Vacuum-filled bulbs wore out quickly.
- Vacuum-filled bulbs became too expensive to produce.
- It became impossible once bulbs were made of thin glass.
What gas fills most light bulbs today?
About what percent of the light from an incandescent bulb is actually visible?
- 10 percent
- 35 percent
- 75 percent
What makes a three-way bulb unique?
- It has two filaments of different wattages.
- It has three separate filaments.
- It combines light-emitting diodes and incandescent and fluorescent light in a single bulb.