3.6: Refraction

Question 1

Refraction

Answer 1

light rays refract (bend) when travelling from one medium to another
(Based of Fermat’s Principle)

Question 2

What is Fermat’s Principle?

Answer 2

light travelling between two points seeks the path that is the FASTESTS

Question 3

Rules for Refraction

Answer 3

• incident rays & refracted rays lie on opposite sides of boundary (line that separates medium)

Question 4

Less dense medium –> denser medium?

Answer 4

refracted ray bends TOWARD normal (smaller angle = slower)

Question 5

Denser medium –> less dense medium?

Answer 5

refracted ray bends AWAY from normal (larger angle = faster)

Question 6

Index of Refraction

Answer 6

the ratio of the speed of light in vacuum to the speed of light in a medium
(amount of light bending depends on index of refraction)

Question 7

Why is index of refraction (n) always more than 1?

Answer 7

always greater than 1 because speed of light in vacuum is faster than in a medium

Question 8

What happens to speed in a medium when index of refraction increases?

Answer 8

larger index of refraction = light travels slower
(n increases = v decreases)

Question 9

How are rainbows made regarding refraction and reflection?

Answer 9

• Refraction of light and water causes different angles that make colour
• light reflects of rainbow into our eyes to become visible