Let's discuss a problem based on light through prisms from Kishore Vaigyanik Protsahan Yojana, KVPY 2010. Try it and then check your solution.
The Problem: Light through Prisms
White light is split into a spectrum by a prism and it is seen on a screen. If we put another identical inverted prism behind in contact, what will be seen on the screen?
(A) Violet will appear where red was
(B) The spectrum will remain the same
(C) There will be no spectrum but only the original light with no deviation
(D) There will be no spectrum, but the original will be laterally displaced
The system will behave as a slab since an inverted prism is put behind in contact with the first prism. Hence, there will be no spectrum, but only original light with no deviation.