Question

A composite light containing yellow, blue and orange colors passes through a prism. Which color bends the most?

Answer 1

The wavelength and frequency of the colors being deviated is different. They get deviated at different angles due to the difference in their velocities in the prism. The color which has the shortest wavelength will bend the most when passed through glass prism.

Complete step by step answer:
Dispersion of white light is the phenomenon of splitting of white light into its constituent spectrum of colors, when it propagates through a glass prism. The figurative meaning of dispersion is distribution, and that’s what actually happens when light passes through glass dispersion; it gets distributed into its constituent colors – violet, indigo, blue, green, yellow, yellow, orange, and red. The white light gets splitted into its constituent colors at various frequencies and various angles.

Dispersion is a material property where the index of refraction is wavelength dependent. As the glass prism has positive dispersion, meaning the index of refraction will increase with the decrease in wavelength. As a result, shorter wavelengths undergo greater degree of refraction than the longer wavelengths.
Formula for angle of deviation inside glass prism:
$\delta =(\mu -1)A$
Where, $\mu$ is the refractive index offered by glass prism and $A$ is the angle of prism.
We are given that a composite light containing yellow, blue and orange colors passes through a prism. As we know, the wavelengths of the colors yellow, blue and orange are in the order,
${{\lambda }_{orange}}>{{\lambda }_{yellow}}>{{\lambda }_{blue}}$
The wavelength of Orange color is the longest and that of Blue color is shortest.

The prism will offer a greater degree of refraction or refractive index to the blue color. Thus, blue light will get spread inside the prism and will deviate or bend the most.

Note: Angle of deviation inside glass prism depends on: Angle of incidence, Angle of prism, and Wavelength of light. The bending occurs during refraction because the light travels slower in a denser medium. The shorter wavelengths of light are slowed more in the denser medium such as prism, and therefore experience more bending than those with the longer wavelengths. The light which has the largest wavelength bends the least while the one with shortest wavelength bends the most.