Learning About Light Bulbs
Flip the switch and trace how electricity becomes the light that brightens a room.
Read along
A light bulb changes electrical energy into light. In an old-fashioned incandescent bulb, electricity flows through a very thin wire called a filament. The filament resists the moving electric current, heats up, and glows. It makes light, but much of the energy becomes heat. Modern LED bulbs work differently. Electricity moves through a semiconductor and releases energy as tiny packets of light called photons. LEDs use less electricity, last much longer, and stay cooler than incandescent bulbs. The switch on the wall completes or breaks the circuit, controlling whether electric current can reach the bulb.
Inside the story
Scene by scene
Pause, look closer, and discover the science behind each part of the adventure.
Scene 0101
Complete the circuit
“Flip the switch and a complete path opens for electric current to move through the lamp.”
A circuit needs a closed loop. Opening the switch breaks that loop, while closing it allows charged particles to move.
Scene 0202
A glowing filament
“Inside an incandescent bulb, a thin filament gets so hot that it shines.”
Electrical resistance heats the tungsten filament to thousands of degrees. Much of the energy is released as heat rather than visible light.
Scene 0303
The efficient LED
“An LED makes light inside a semiconductor, using less energy and lasting for years.”
When electrons cross part of the semiconductor, they release photons. This direct process wastes less energy as heat.
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