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LP - 2 ટિપ્પણી-કમ
9. 4449112840, agd 284} foda (laly zulalil), 4. 94. 2. 284, 49 90, 91, 96 ૩. બલ્બમાં ટંગ્ટનના તારની પસંદગી કેમ થાય છે, એ નિમ્ન ઉદ્ધરણથી
248 2414 9. (-226zell 20141)
"How does a regular lamp (light b ulb) work? A normal incandescent lamp contains a double-wound tungsten filament inside a gas-filled glass bulb. By "double-round", I mean that a very fine wire is first wound into a long, thin spiral and then this spiral is again wound into a wider spiral. While the final filament looks about I or 2 centimeters long, it actually contains about 1 meter of fine tungsten wire. When the bulb is on, an electric current flows through the filament from one end to the other. The electrons making up this current carry energy, both in their motion and in the forces that they exert on one another. As they flow through the fine tungsten wire, these electrons collide with the tungsten atoms and transfer some of their energy to .those tungsten atoms. The tungsten atoms and the filament become extremely hot, typically about 2500° Celsius. Tungsten wire is used because it tolerates these enormous temperatures without melting and because it resists sublimation longer than any other material. Sublimation is when atoms "evaporate" from the surface of a solid. The gas inside the bulb is there to slow sublimation and extend the life of the filament. Once the filament is hot, it tends to transfer heat to its colder surroundings. While much of its heat leaves the filament via convection and conduction in the gas and glass bulb, a significant fraction of this heat leaves the filament via thermal radiation. For any object that is hotter than about 500° Celsius, some of
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