19. When white light is incident on a prism, which one of the resulting color components will have the lowest index of refraction? A. Orange B. Blue C. Yellow D. Green

option A

Explanation:

When white light is incident on prism it bends and dispersed into different colors.

According to Cauchy equation, refractive index is inversely proportional to the wavelength of the light.

wavelength of the light in decreasing order

orange > yellow > green > blue

wavelength of the orange light is the highest.

Hence, the refractive index of orange will be lowest.

The correct answer is option A