Quiz: How does a light bulb work?
by Staff
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
  • millions

What are light particles called?

  • photons
  • electrons
  • protons

Which of these weighs the least?

  • photons
  • electrons
  • protons

When an electron has more energy, will it be closer, farther or the same distance from the nucleus of the atom?

  • farther
  • closer
  • 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?

  • one
  • two
  • three

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?

  • argon
  • radon
  • xenon

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.