Light bulb. Coloured X-ray of an electric light bulb. At upper centre,the coiled filament can be seen inside the glass envelope. The filament is doubly coiled. A fine tungsten wire (about 0.01mm thick) is wound into a helical coil,and then wound into a larger diameter helical coil. Tungsten is ideal for a filament as it is strong and has a high melting point (3410 degrees Celsius). The glass bulb is filled with an inert nitrogen/argon mixture to prevent oxidation. As the bulb runs,however,small amounts of tungsten deposit onto the glass. Eventually,this results in a break in the filament and the bulb "blows". The average life of such a bulb is 1,000 hours | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Gustoimages |
Bildgröße: | 2865 px × 3578 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |