1-The study of properties and behaviour of light is known as Optics.
2-Holography -Three dimensional imaging using interference of light
3-Colour of light with longest wavelength is Red.
4-Colour of light with smallest wavelength is violet.
5-Blue light is most conducive to photosynthesis.
6-Rainbows are formed due to dispersion of light.
7-Beautiful colours are seen in soap bubbles and oil films on water due to Interference of light.
8-Sky appears blue and Sun appears red during sunrise and sunset due to scattering of light rays of small wavelengths
9-Refraction of light and its visible effects are as follows-
a-Stick immersed in water appears bent at the point of separation.
b-Sun or moon appears larger in size when at horizon.
c-Day is lengthened, stars appear to twinkle and mirages are formed.
d-A person standing inside water appears shorter.
10- The speed of light is 186,000 miles per second or 300,000,000 m/s
11-LASER -System of light excitation used in surgeries,printers etc.