Atay of light passes from the air (refractive index 1.00) to water (refractive index 1.33). The ratio (v₁/v₂) of the speed of light in the air (v₁) to that in water (v₂) is ______ and the ray bends _______ the normal after refraction. 

The correct answer is 1.33; towards.

Key Points

• The speed of light in a medium is inversely proportional to the refractive index of the medium.
• The refractive index of air is 1.00 and that of water is 1.33.
• The ratio of the speed of light in air (v₁) to that in water (v₂) is given by v₁/v₂ = n₂/n₁ = 1.33/1.00 = 1.33.
• When light passes from a medium with a lower refractive index to a medium with a higher refractive index, it slows down and bends towards the normal.
• Hence, the ray of light bends towards the normal when it passes from air to water.

Additional Information

• Snell's Law
  • It states that the ratio of the sines of the angles of incidence and refraction is constant, and equivalent to the ratio of the phase velocities in the two media.
  • It is given by the formula: n₁ sin(θ₁) = n₂ sin(θ₂).
• Critical Angle
  • The angle of incidence above which total internal reflection occurs.
  • It occurs when light passes from a medium with a higher refractive index to one with a lower refractive index.
• Dispersion
  • It is the phenomenon in which the phase velocity of a wave depends on its frequency.
  • In optics, dispersion is most often described as the wavelength-dependent refractive index of a material.