Why do light bulbs burn out when turned on, but not while shining?

In summary, an electric light bulb is more likely to burn out when it is first turned on because the filament rapidly expands as it becomes hotter. Once the bulb reaches a steady-state, the filament no longer expands and the chance of it breaking decreases. This effect is amplified when using a cheap dimmer switch, as the choppy power supply can cause the filament to oscillate and buzz, leading to a higher chance of burning out. Higher quality dimmer switches have components to smooth out the power supply and reduce this risk.
  • #1
9danny
10
0
Why does an electric light bulb nearly always burns out just as you turn on the light, but almost never while the light is shining? :confused:
 
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  • #2
The filament is rapidly becoming hotter, and thus rapidly undergoing thermal expansion. During this expansion, any small imperfection may cause it to break.

Once the bulb is in steady-state, the filament no longer grows hotter, and no longer expands.

- Warren
 
  • #3
The effect is much worse if your bulb is being dimmed by a cheap dimmer switch, because even though the filament is getting less power, it's getting it in a very choppy form that often causes the filament to oscillate and buzz. Better dimmers have a choke and some capacitors to help smooth out the choppy signal coming from the triac.
 

1. What is the story behind "Once upon a light bulb"?

The story is about an inventor who creates a revolutionary light bulb and the challenges he faces in trying to bring it to the world.

2. Is "Once upon a light bulb" based on a true story?

No, it is a work of fiction. However, it is inspired by the many inventors and their struggles to bring their inventions to the world.

3. What lessons can be learned from "Once upon a light bulb"?

The story highlights the importance of perseverance, determination, and overcoming obstacles in achieving success. It also emphasizes the impact of innovation and invention on society.

4. Who is the target audience for "Once upon a light bulb"?

The target audience is primarily children and young adults, but the story can be enjoyed by people of all ages. It aims to inspire and educate readers about the process of invention and the power of imagination.

5. Are there any sequels to "Once upon a light bulb"?

At the moment, there are no sequels to the story. However, the author has expressed interest in continuing the story in the future.

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