Question

(i) What is visible spectrum?
(ii) Why is red used as the stopping light at traffic signals?
(iii)Two triangular glass prisms are kept together connected through their rectangular
side. A light beam is passed through one side of the combination. Will there be any
dispersion? Justify your answer.​

Answer 1

Answer:

visible spectrum is that in which we can see in the electromagnetic spectrum i.e light which ranges between 340-780 nm

red has longest wavelength due to which it can be seen from a long distance

Explanation:

white light will get dispersed into seven colours but in second prism it will get recombined to form white light

Answer 2

Answer:

1) visible spectrum is the portion of the electo magnetic spectrum that is visible to the human eye.

2) the red light is scattered the least by air molecules.