Refraction

Physics: Cambridge International GCSE Supplement, topic 3.2.3

Refraction of Light

Light is refracted when it travels from one medium to another and changes speed.

Optically dense materials

Optically dense materials

  • If light slows down as it enters a new medium, this medium is “more optically dense”.
  • When light enters a more optically dense medium, it is refracted closer to the normal.
  • This means that the angle of refraction is smaller than the angle of incidence.
Less optically dense materials

Less optically dense materials

  • If light speeds up on entering a new medium, this medium is “less optically dense”.
  • The light is refracted further from the normal - the angle of refraction is larger than the angle of incidence.

Test yourself on Refraction

  • What happens to the angle of refraction when light enters a less optically dense medium and speeds up?

  • What happens to light entering a material with higher optical density?

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