Light passing through a PRISM is dispersed because different colours of light have

1. NCERT §9.7 (Refraction through a Prism + Dispersion): the refractive index of any medium depends on the WAVELENGTH of light. 2. Typically $n$ DECREASES with wavelength (normal dispersion): violet light has higher $n$ than red light in glass. 3. Snell's law then bends different colours by different amounts: violet bends MORE than red. This is DISPERSION. 4. After two refractions through a prism (entry + exit), the colours emerge in a fan of different deviation angles — the visible spectrum. 5. Newton's classic experiment confirmed white light is a mixture; the prism doesn't 'colour' the light, it just separates the components. 6. Option A is wrong — in vacuum, all colours have the same speed $c$. Option C confuses frequency (which is unchanged across media) with refractive index. Option D ignores the physics. _Source: NCERT Class 12 Physics Part 2, Ch 9, §9.7 (Refraction through a Prism — dispersion by a prism), p. 22–24._