Question

The dispersion of white light when it passes through a prism shows that

• A. all colours in white light have the same speed.
• B. white light is monochromatic.
• C. the speed of light in a vacuum is a constant.
• D. different colours have different indices of refraction in the prism.

Answer 1

The correct option is D different colours have different indices of refraction in the prism.

• Dispersion of white light through a prism shows that different wavelengths (colours) of light travel through a medium at different speeds.
• The amount of bending is different for different wavelengths.
• Violet bends the most and red the least because violet light has a shorter wavelength.
• So, different colours have a different refractive index in the prism.