When a white light beam is made to fall on a hollow prism filled with water, it breaks into seven constituent colours. Which of the following colours suffers the maximum angle of deviation?

When white light passes through a prism, it undergoes dispersion, which is the splitting of light into its constituent colors [1]. This phenomenon occurs because the refractive index of a medium, such as water or glass, is not constant but varies with the wavelength of light [3]. Shorter wavelengths, such as violet light, experience a higher refractive index compared to longer wavelengths like red light [5]. According to Snell's law, a higher refractive index results in a greater degree of bending or refraction [3]. Consequently, violet light travels more slowly in the medium and suffers the maximum angle of deviation from its original path [5]. In contrast, red light, having the longest wavelength in the visible spectrum, bends the least [4]. Therefore, in a water-filled hollow prism, violet light will always exhibit the most significant deviation.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 10: The Human Eye and the Colourful World > Activity 10.2 > p. 167
2. [3] Science , class X (NCERT 2025 ed.) > Chapter 9: Light – Reflection and Refraction > Activity 9.10 > p. 148
3. [5] https://en.wikipedia.org/wiki/Dispersive_prism
4. [2] Science , class X (NCERT 2025 ed.) > Chapter 10: The Human Eye and the Colourful World > 10.3 REFRACTION OF LIGHT THROUGH A PRISM > p. 165
5. [4] https://www.sciencedirect.com/topics/mathematics/prism