Solution:
The answer is (b) (ii)
If the prism is kept with BC at the bottom, a band of colour appears at the bottom that is violet. If the prism is kept with BC at the top, violet will be at the top of the prism, followed by indigo, blue, and green.
A prism ABC (with BC as a base) is placed in different orientations. A narrow beam of white light is incident on the prism as shown in Figure 11.1. In which of the following cases, after dispersion, the third colour from the top corresponds to the colour of the sky? The Human Eye and the Colourful World CHAPTER11 Fig.11.1
(a) (i)
(b) (ii)
(c) (iii)
(d) (iv)