Wonders of light part One.

If refractive index of 2nd medium with respect to 1st medium is 2 then what is the refractive index of 1st medium with respect to 2nd medium. 

Ans. The refractive index of 1st w.r.t. 2nd and 2nd w.r.t. 1st are reciprocal.
2. When light travels from rarer medium to denser medium. If the angle of incidence is 30o can the angle of refraction be 41o. Why ?
Ans. (a) No, because when the light travels from rarer to denser it will bend towards the normal.
(b) Hence the angle of refraction will be less than angle of incidence.
3. Traffic signal does not use violet colour.
Ans. (a) During dispersion of light amongst red, orange, yellow, green, blue
indigo and violet, violet turns the most.
(b) Because of this it would not be visible to a far away person.
4. When light travels from water to alcohol, where will it bend. Ans. (a) The refractive index of water is 1.36 and alcohol is 1.44.
(b) Hence water is rarer medium as compared to alcohol. (c) So light will bend towards the normal.
5. A person walking in desert gets a illusion of seeing water. Name the phenomenon of light responsible for it.
Ans. The phenomenon is called as mirage, it happens because of total internal reflection.