Q1. [1] § 10.3 REFRACTION OF LIGHT THROUGH A PRISM § 10.4 DISPERSION OF WHITE LIGHT BY A GLASS PRISM
Observe the given ray diagram showing refraction through a prism and choose the correct option for colour of rays 1 and 2 :
- (A) Colour of ray 1: Blue; Colour of ray 2: Red
- (B) Colour of ray 1: Green; Colour of ray 2: Yellow
- (C) Colour of ray 1: Red; Colour of ray 2: Violet
- (D) Colour of ray 1: Violet; Colour of ray 2: Red
Previously asked in CBSE board exam
2026 31/3/1 Q31
Generated by claude-sonnet-4-6 · 2026-06-15 06:51 · grounding rag
Model Answer
(C) Colour of ray 1: Red; Colour of ray 2: Violet
Red light bends the least and violet bends the most while passing through a prism. So Ray 1 (less deviated) is red and Ray 2 (more deviated) is violet.
Explanation
The key fact from the textbook (Section 10.4) is: "The red light bends the least while the violet the most." In a prism dispersion diagram, the ray closest to the original direction of white light is red, and the most deviated ray is violet. Examiners expect you to directly apply VIBGYOR and the deviation rule.
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