A ray of light passes from a slab of glass (refractive index 1.50) to water (refractive index 1.33). The ratio (v₁/v₂) of speed of light in glass (v₁) to that in water (v₂) is ______ and the ray bends ______ the normal after refraction.

The correct answer is 0.89; away from the normal.

Key Points

• The refractive index of glass is 1.50, while that of water is 1.33.
• The speed of light in a medium is inversely proportional to its refractive index, hence v1/v2 = 1.33/1.50.
• This ratio (v1/v2) calculates to approximately 0.89.
• When light passes from a denser medium (glass) to a less dense medium (water), it bends away from the normal.

Additional Information

• Refractive Index
  • It is a measure of how much the speed of light is reduced inside a medium compared to the vacuum.
  • Higher refractive index means the medium is optically denser.
• Snell's Law
  • It states the relationship between the angles of incidence and refraction when light passes through different media.
  • The law is given by n1*sin(θ1) = n2*sin(θ2).
• Critical Angle
  • It is the angle of incidence above which total internal reflection occurs.
  • It occurs when light tries to move from a denser medium to a less dense medium.
• Total Internal Reflection
  • It happens when the angle of incidence is greater than the critical angle.
  • Light does not pass into the second medium but is entirely reflected back into the first medium.