The filament is made out of tungsten, why?

REASON FOR USING TUNGSTEN TO MAKE THE FILAMENT:

The filament is a small thin wire between two big wires which is generally found in light bulbs.  The electric current passes through filament and produce the light.

Hence the filament material need to handle high temperature. It also has to handle expansion and contraction while the heating and cooling. So the material need to be more flexible. In this case tungsten has a high melting point and can handle the heat and also the expansion and reduction well.  Hence, Tungsten is used for making the Filament.

1.   what is light?

light is an electromagnetic wave visible to the human eye. 

2. what is a reflection?

the rebounding of a light ray when it hits a mirror.

3. what is the incident ray?

contacts the surface of an object.

4. what is the reflected ray?

bounces off a reflective surface.

5. what is the normal ray?

perpendicular to the surface of a mirror.

6. what is the angle of incidence?

an angle formed by the incident ray and the normal.

7. what is the angle of reflection?

an angle formed by the reflected ray and the normal.

8. what is refraction?

(bending.)

9. what is a converging lens?

bring together light rays that pass through.

10. what is a diverging lens?

spreads out light passing through.

11. focal point?

the real point where the refracted rays meet when the incident rays run parallel.

i copy pasted btw from an website..