লাইট বাল্বের ফিলামেন্টটি __________ দ্বারা গঠিত।

Incandescent bulb filaments are made of tungsten, because it has the highest melting point of all metals (about 3,422 °C) and can glow white-hot without melting. The bulb is filled with an inert gas so the filament does not oxidise.