Question

Calculate speed of light in water of refractive index `4//3`. Given speed of light in air `= 3 xx 10^(8) m//s`.

Answer 1

Correct Answer - `2.25 x 10^(8)m//s`
Here, `.^(a)n_(w) = 4//3, v_(a) = 3 xx 10^(8) m//s, v_(w) = ?`
From `.^(a)n_(w) = (v_(a))/(v_(w))`
`v_(w) = v_(a)/(.^(a)n_(w)) = (3xx 10^(8))/(4//3) = 2.25 xx 10^(8) m//s`