The answer to the question "Filament of electric bulb is made up of" is B: Tungsten.

Explanation:

Introduction:
The filament is the part of an electric bulb that emits light when an electric current passes through it. It is a crucial component of an incandescent bulb as it produces the illumination. The filament needs to have certain properties in order to function effectively, such as high melting point, resistance to oxidation, and durability.

Tungsten Filament:
1. The filament of an incandescent electric bulb is typically made up of tungsten.
2. Tungsten is a metal known for its high melting point, which is around 3,410°C (6,170°F).
3. Its high melting point ensures that the filament does not melt or vaporize easily when it becomes heated.
4. Tungsten also has a low coefficient of thermal expansion, meaning it does not expand or contract significantly when exposed to high temperatures.
5. This property helps maintain the stability and integrity of the filament during the heating and cooling cycles.
6. Tungsten is a highly durable material, allowing the filament to withstand the repeated heating and cooling without breaking or deforming easily.
7. Additionally, tungsten has a high electrical resistance, which is essential for generating the required amount of heat to produce light.
8. The resistance of the filament causes it to become extremely hot when an electric current passes through it, resulting in the emission of visible light.

Advantages of Tungsten Filament:
- Tungsten filaments have a longer lifespan compared to filaments made from other materials.
- They can operate at higher temperatures, resulting in a brighter and more efficient light output.
- Tungsten filaments also have better resistance to evaporation and can withstand higher currents without degrading quickly.

Conclusion:
The filament of an electric bulb is made up of tungsten due to its high melting point, low thermal expansion, durability, and high electrical resistance. These properties ensure that the filament can produce light efficiently and have a longer lifespan.

Tungstèn