Question

While playing with prisms, Sushweta arranged three prisms as shown below ($2^{nd}$ prism inverted with respect to the other two) and made sunlight fall on the $1^{st}$ prism.

The colour(s) she would observe in regions A, B and C are respectively:

• A. Band of 7 colors, Band of 7 colors, Band of 7 colors
• B. White light, Band of 7 colors, White light
• C. Band of 7 colors, White light, Band of 7 colors
• D. Band of 7 colors, Band of 7 colors, White light

Answer 1

The correct option is C

Band of 7 colors, White light, Band of 7 colors

The first prism will disperse white light into seven colours, so we will get a band of 7 colours in region A. The $2^{nd}$ prism will recombine these seven colours to give white light in region B. The $3^{rd}$ prism, just like the $1^{st}$ one, will again produce a band of 7 colours in region C.