Question

The velocity of light in glass is 2 x 10⁸ m/s. If the refractive index of glass with respect to water is 9/8, then the velocity of light in water is ______

Options

• 1.6 x 10⁸ m/s

• 1.33 x 10⁸ m/s

• 3 x 10⁸ m/s

• 2.25 x 10⁸ m/s

Answer 1

The velocity of light in glass is 2 x 10⁸ m/s. If the refractive index of glass with respect to water is 9/8, then the velocity of light in water is 2.25 x 10⁸ m/s.

Explanation:

`""^"w""n"_"g" = "v"_"w"/"v"_"g"`

⇒ `"v"_"w" = ""^"w""n"_"g" xx "v"_"g" = 9/8 xx 2 xx 10^8 = 2.25 xx 10^8` m/s