Question

If the absolute refractive indices of water and glass are 4/3 and 3/2 respectively, then what will be the ratio of velocity of light in water to that of glass ?(A) 2
(B) 8/9
(C) 9/3
(D) 1/2

Answer 1

Answer ⇒ No option is correct.

Explanation ⇒ ''Absolute refractive index of the materials is defined as the ratio of the speed of the light in air to the speed of the light in that medium.''

''Mathematically, It can be expressed as, Absolute Refractive Index = Speed of Light in air/Speed of light in that medium.''

For water,

Absolute Refractive Index = 4/3

Speed of light in air = 3 × 10⁸ m/s.

Using the Formula,

4/3 = 3 × 10⁸/v₁

∴ v₁ = 9/4 × 10⁸ m/s.

Similarly, for glass,

v₂ = 2 × 10⁸ m/s.

∴ Ratio of v₁ and v₂ = (9/4 × 10⁸)/(2 × 10⁸)

= 9/8

= 9 : 8

''There is no such option. Hence, there is either the typing errors or mistakes.''

''Correct answers and its calculation is shown above.''

Hope it helps.