For which of the following media is the absolute refractive index almost equal to one?

Option 2 : Air

The correct answer is Air.

• Refractive Index of a medium: 
  • It tells the capacity of the medium to bend a light ray when it passes through.
  • The Refractive index is inversely proportional to the speed of the light.
  • It is a dimensionless quantity.
• The absolute refractive index of a medium:
  • It is expressed as the ratio speed of light in vacuum to the speed of light in the medium.
  • It is a comparison of the speeds of light of different media.
  • The speed of light in air is almost equal to the speed of light in a vacuum. So, absolute refractive index, μ = c / c = 1.