There is a very thin and curved tungsten wire in the light bulb. When the switch of the lamp is turned on, the current will enter the bulb through the wire. When the current passes through the tungsten wire, the temperature of the tungsten wire will rise. When its temperature rises to a certain extent, it will emit heat and light, so the light bulb will be lit.
Extended data
Structure and principle of electric light bulb;
The filament of an electric light bulb is spirally wound with a thin tungsten wire. Generally, tungsten filament will start to glow when heated to 100℃. Tungsten wire can withstand the high temperature of 2300℃ ~ 2500℃. In an electric light bulb made of glass, air is pumped out, nonflammable gases such as nitrogen and argon are filled in, and then sealed, and it becomes an electric light bulb.
When the current flows from the wire into the filament (tungsten filament), because the resistance of the filament is quite large, it generates high heat, and when it is hot enough, it will emit light. The light bulb is "glowing with heat", so it is very hot. Don't touch it with your hands.
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