Quizmo

Quiz on The Light Bulb

20 questions · June 29, 2026

Below is the full Quizmo quiz devoted to the theme "The Light Bulb": each question, its four options, the correct answer highlighted and, where available, its source. A chance to brush up on your general knowledge and then test what you know.

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Question 1

Easy

Which inventor is most associated with inventing the light bulb?

Source: Edison didn't invent it alone—Britain's Joseph Swan lit one up first.

Question 2

Easy

A glowing bulb drawn above a cartoon character means they just had a what?

Source: The 'idea bulb' was popularized by early Felix the Cat and Disney cartoons.

Question 3

Easy

Which modern bulb uses the least electricity for the same brightness?

Source: LEDs can use up to 90% less energy than old-style bulbs.

Question 4

Easy

What does the 'LED' in an LED bulb stand for?

Source: A diode emits light only when current flows the right way through it.

Question 5

Easy

The thin glowing wire inside a traditional bulb is called the what?

Source: Edison's first long-lasting filament was made from carbonized bamboo.

Question 6

Easy

On bulb packaging today, brightness is actually measured in what?

Source: Watts measure energy used, not brightness—a very common mix-up.

Question 7

Easy

Most of the energy from an old incandescent bulb is released as what?

Source: Only about 5% becomes light; the rest is wasted as heat.

Question 8

Easy

'Warm white' lighting glows closest to which color?

Source: 'Cool white' leans blue—'warm' here means hue, not temperature.

Question 9

Easy

Switching a light off when you leave a room mainly saves what?

Source: A single bulb left on all year can quietly add up on the bill.

Question 10

Easy

A screw-in bulb twists into a fitting commonly called a what?

Source: That spiral thread is still officially called the 'Edison screw.'

Question 11

Medium

Who demonstrated a working incandescent bulb in Britain before Edison?

Source: Edison and Swan later merged their firms into 'Ediswan.'

Question 12

Medium

An inert gas inside many incandescent bulbs stops the filament from doing what?

Source: Argon and nitrogen push out oxygen so the filament can't catch fire.

Question 13

Medium

A California fire station keeps a bulb that is famous for what?

Source: The Centennial Light runs cool and dim, which is why it lasts.

Question 14

Medium

Halogen bulbs are an improved version of which older technology?

Source: Halogen gas lets the filament burn hotter and brighter without wearing fast.

Question 15

Medium

Compact fluorescent bulbs contain a small amount of which toxic element?

Source: That trace of mercury vapor is why CFLs must be recycled carefully.

Question 16

Medium

The earliest electric streetlights mostly used which kind of lamp?

Source: Arc lamps were blindingly bright—far too harsh for indoor homes.

Question 17

Medium

A bulb's 'color temperature,' measured in Kelvin, actually describes what?

Source: Higher Kelvin means bluer light, even though it sounds hotter.

Question 18

Hard

Edison promoted DC power in a famous feud against whose AC system?

Source: AC won because it travels long distances far better than DC.

Question 19

Hard

A 1920s makers' cartel is accused of deliberately doing what to bulbs?

Source: The Phoebus cartel capped bulb life near 1,000 hours—planned obsolescence.

Question 20

Hard

Before tungsten, early commercial bulb filaments were often made from what?

Source: Edison tested thousands of materials before bamboo, later beaten by tungsten.

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