Question

1. Is light a wave phenomenon? Explain.

2. Why is it not possible for the human eye to see the frequencies of infrared      light? Explain.

3. Why is it possible to see colors? Explain.

4. Mention and explain an everyday phenomenon in which the dispersion of light can be observed.

Answer 1

answer 1. In laboratory prism is used to demostrate the dispersion of light.

Justification: Prism's refractive index depends upon the incident radiations's frequency. This dependence on frequency makes the light both makes the light of different frequency to move at different velcoty inside the prism and also to have a different angle of refraction from both first(incident surface) and second(emerging surface). This having different angle of refraction when incident on the prism makes the light to get dispers.

answer2. Rainbow is a phenomenon that demostrate the phenomenon of dispersion of light.

When sun rays, hits the rain drops(drops in air, in general), the refractive angle for different frequency of light is different, this makes the rain drop to disperse the light. This disperesed light get's internally reflected(actually total internal reflection), and we see rainbow.

3. Different colours have different frequency. Our eyes have different colours sensors(the retina has different colour sensors). Rods and Cons. They are responsible to detect and differentiate between colours.

True or false

1. False. Dispersion has nothing to do with obstacle dimention. It is related to the refractive index of the medium through which the light passes after entering.

2. True. Dispersion is the breaking of complex(white light) to it's individual component colors.

3. False. Our eyes cannot detect Infrared light, hence we cannot see dipersion of Infrared by prism.

4. False. Relection is a phenomenon in which an incident ray on a surface, some of it's intensity get's into the second medium and some intensity moves(at the same angle of that of incident) in the same medium. This is known as relection.