Question

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 it in contact, what will be seen on the screen?

• A. Violet will appear where red was
• B. The spectrum will remains same
• C. There will be no spectrum, but only the original light with no deviation
• D. There will be no spectrum, but the original light will be laterally displaced

Answer 1

Answer: (D)

First prism separates white light into its constituent colours which are then recombined by the second inverted prism into white light.

As two prisms combinedly form a glass slab, light beam is deviated on a parallel path.