SP5 light and electromagnetic spectrum

Question 1

Law of reflection

Answer 1

Angle of refraction = angle of reflection

Question 2

What is total internal refraction

Answer 2

Complete reflection of a ray of light within a medium such as water or glass from the surrounding surfaces back into the medium.

Question 3

Explain the significance of the critical angle in

total internal reflection.

Answer 3

When the angle of incidence equals the critical angle, the refracted light passes along the interface boundary of the glass.

Question 4

Explain the difference between specular and

diffuse reflection.

Answer 4

Reflection from a smooth, flat surface is called specular reflection . This is the type of reflection that happens with a flat mirror. If a surface is rough, diffuse reflection happens. Instead of forming an image, the reflected light is scattered in all directions.

Question 5

What is white light

Answer 5

A mixture of different colours of light

Question 6

Explain why surfaces appear to have different

colours in terms of differential absorption.

Answer 6

Explain why surfaces appear to have different

colours in terms of differential absorption.

Question 7

Explain how filters make coloured light in terms of absorption and transmission.

Answer 7

When white light passes through a coloured filter, all colours are absorbed except for the colour of the filter.

Question 8

Explain the effect of viewing coloured objects

in different colours of light.

Answer 8

Objects appear different colours because they absorb some colours (wavelengths) and reflected or transmit other colours.