Question

Give reasons:
(i) The extent of deviation of a ray of light on passing through a glass prism
depends on its colour.
(ii) Lights of red colour are used for danger signals.

Answer 1

Answer:

1.the extent of deviation of a ray of light on passing through a glass prism depends on its colour. ... It is found that refractive index is different for different color of light. It is minimum for red light and maximum for violet light. Hence, deviation is minimum of red light and maximum for violet light.

2.Red colour is always used for danger signals, because as red colour is having the longest wavelength, it is the least scattered. So, this signal can be seen from a very long distance.

Answer 2

Answer:

(i) Refractive index of a medium and wavelength is different for different colours of light.  

(ii) Due to larger wavelength, red colour scatters the least and can travel to larger distances.