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Question
If the absolute refractive index of water is 1.36, find the speed of light in water. (Speed of light in vacuum = 3 × 108 m/s.)
Solution
Given: Absolute refractive index of water (n) = 1.36,
Velocity of light in vacuum (v1) = 3 × 108 m/s
To find: Velocity of light in water (v2)
Formula: n = `"v"_1/"v"_2`
Calculation: From formula,
`"v"_2 = "v"_1/"n"`
`= (3 xx 10^8)/1.36`
= 2.21 × 108 m/s
The velocity of light in water is 2.21 × 108 m/s.
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