Question

If a beam of white light falls on the system of prisms shown, what will be the output coming from the third prism?

• A. White light
• B. Standard VIBGYOR (violet below and red on top)
• C. Reverse VIBGYOR (red below and violet on top)
• D. Seven colours arranged in a random manner

Answer 1

The correct option is B Standard VIBGYOR (violet below and red on top)

• The first prism causes the dispersion of the white ray.
• The second prism causes the reunification of all the colours and produces white light.
• The third prism disperses the unified white light as shown.