When white light passes through a glass prism and forms a spectrum, which colour bends the least and which bends the most?
Generated by claude-sonnet-4-6 · 2026-06-26 01:06 · grounding rag
Model Answer
When white light passes through a glass prism, it undergoes dispersion — splitting into its seven component colours (VIBGYOR).
- Red light bends the least (smallest angle of deviation).
- Violet light bends the most (largest angle of deviation).
Different colours of light bend through different angles with respect to the incident ray as they pass through the prism. This is why the rays of each colour emerge along different paths, forming a distinct spectrum on the screen with red at one end and violet at the other.
Source: Chapter 10, Section 10.4 — Dispersion of White Light by a Glass Prism
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Explanation
- The examiner expects you to name both colours clearly and directly — Red (least) and Violet (most).
- Mentioning dispersion and VIBGYOR shows conceptual understanding and earns method marks.
- The reason (different colours bend by different angles) is essential for full marks on a 3-mark question.
- Do not confuse the order: Red is at the top of the spectrum (least bent), Violet at the bottom (most bent).