P5 - Refraction of waves

Question 1

When does refraction occur?

Answer 1

Refraction occurs when light passes from one medium to another.

Question 2

Why does dispersion occur?

Answer 2

Dispersion occurs when light passes through a medium such as glass or water.

Question 3

Which colour is refracted the most and why?

Answer 3

Violet and blue light have the shortest wavelength and are bent the most.

Question 4

When does total internal reflection occur?

Answer 4

• when light passes from materials like glass or water to air
• when the angle of incidence is larger than the critical angle

Question 5

What are the uses of total internal reflection?

Answer 5

• optical fibres to transmit pulses of light
• binoculars to shorten their length
• bicycle reflectors so that the bicycle is seen in a car’s headlights
• cats eyes to mark the centre of a road in the dark