A ray is a straight line drawn to represent the direction that a light wave travels.

The normal is an imaginary line drawn at 90° to a surface.

Wavefronts are lines drawn to represent peaks of a wave.

Reflection of light

Combined science

In A-level physics, some pupils will build on this knowledge to learn about the photon model of electromagnetic radiation and the use of electromagnetic radiation for collecting evidence about the universe or for generating images of the inside of a human body.

In the Measuring waves unit, pupils learnt about the measurable features of a wave, the relationship between them and the wave equation.

This unit explores reflection, refraction, and lenses using ray diagrams. It covers the electromagnetic spectrum, light as a wave, absorption, transmission, and practical uses. Emphasis is on risks, temperature balance, data presentation, and unit conversions.

Electromagnetic waves

an imaginary line drawn at 90° to a surface

a straight line drawn to show the direction a wave travels

a line drawn to represent where the peak of a wave is

The ray in the diagram represents one of the many rays that make up the light.

The length of the ray represents the wavelength of the wave.

The arrow shows the direction in which energy is transferred.

A ray diagram shows a light ray. Which statement about the ray is correct?

Speaking transfers some energy from the speaker to the listener.

Speaking makes air particles travel from the speaker to the listener.

A person speaks to another person across a room. Which statements are correct?

The incident ray equals the reflected ray.

The angle of incidence equals the angle of reflection.

The incident ray is perpendicular to the reflected ray.

The angle of incidence and the angle of reflection add to 90°.

Which statement describes the law of reflection?

Here is a ray diagram for the reflection of a wave. In which diagram is the angle of reflection shaded?

The ray diagram represents the reflection of a light wave by a mirror. Which diagram correctly shows the wavefronts?

this is the angle between one side of a square and the next side

if you turn by this angle, you face in the opposite direction

if you turn by this angle, you face in the same direction as before

The protractor is measuring the angle between the two lines. What is the correct measurement?

Which letter is labelling a peak (also called a crest) of this wave? 

A person holds a lit candle in front of a mirror and is looking at the candle’s reflection. Starting with where the light is given out, put these objects into the order of the path the light takes.

the light enters the object but does not come back out

the light bounces off the surface of the object

the light continues travelling in the same direction

What happens to light when it reflects off an object?

Starter Quiz