dispersion concept

Question

Dispersion refers to separation of white light into colors due to variation of?

RankGuru · Accepted Answer

1. **Definition of Dispersion**: The splitting of white light into its constituent colors (VIBGYOR) when passing through a medium like a prism.
2. **Cauchy's Relation**: In transparent media, the refractive index ($n$) is not a constant but depends on the wavelength ($\lambda$). Typically, $n(\lambda) = A + B/\lambda^2$.
3. **Refraction Angle**: Since $n$ varies with $\lambda$, the angle of refraction (from Snell's Law) will be different for each color.
4. **Outcome**: Violet light (shorter $\lambda$) has a higher $n$ and deviates the most; Red light (longer $\lambda$) has a lower $n$ and deviates the least.
5. **Conclusion**: Dispersion is a direct consequence of the **wavelength dependence of the refractive index**.

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dispersion concept

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