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The refractive index of water is 1.33. The speed of light in water (in m/s) is approximately:
Answer & Solution
Correct answer: D.
1. v = c/n = (3 × 10⁸)/1.33.
2. Calculation: 3 × 10⁸ ÷ 1.33 ≈ 2.26 × 10⁸ m/s.
3. Hence light slows to ~226,000 km/s in water.
_Source: NCERT Class 10 Science, Ch 9 "Light Reflection and Refraction", §9.3.1_
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