Lesson T4.2.5

T4.2.5 Colours and prisms Quiz: KS3 Physics, Unit 4

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

In partnership with Revision Ninja

Lesson T4.2.5, Colours and prisms: 20 multiple choice questions for the KS3 Physics (National Curriculum), Unit 4: Waves, written with Revision Ninja.

Host it live on the board and students join with a game code on their own devices, or revise alone with Free Play. The answers are revealed in the game.

Host this setFree Play

The 20 questions

  1. What does white light consist of?

    • A single colour with no others present, which is why it looks so bright and clean
    • Only red, green and blue light with nothing else, which mix to form all other colours
    • A mixture of all the visible colours of light
    • Light with no frequency at all, which means that it has no particular colour to it

  2. What happens when white light passes through a prism?

    • It becomes darker and turns grey, because the prism removes a large part of the light's energy.
    • It is absorbed completely by the glass, so that no light emerges from the far side of the prism.
    • It turns into a single coloured beam, which takes on the colour of the glass inside the prism.
    • It splits into a spectrum of colours.

  3. Which colour of visible light has the highest frequency?

    • Violet
    • Red, which is the colour at the other end of the visible spectrum from violet light
    • Orange, which lies between red and yellow in the visible spectrum of colours
    • Yellow, which is the brightest colour to the eye but lies near the middle of the spectrum

  4. Which colour of visible light has the lowest frequency?

    • Violet, which has the shortest wavelength and the highest frequency in the visible spectrum
    • Blue, which lies in the middle of the spectrum between green and indigo in colour order
    • Red
    • Green, which lies in the middle of the visible spectrum near the brightest part of the eye's view

  5. Why does a red object look red in white light?

    • It reflects red light and absorbs most of the other colours.
    • It transmits red light and blocks all the others, so that only red light reaches the eye.
    • It emits red light from inside the object, which is produced by the object's own heat.
    • It absorbs red light and reflects all the others, which is why it appears red to the eye.

  6. What colour does a blue object appear in red light?

    • Blue, because the object keeps its colour whatever kind of light falls on its surface
    • Black
    • Green, because the object mixes the red light with its own blue colour to make green
    • Red, because the object reflects the colour of the light that falls onto it in every case

  7. In what order do the colours of the rainbow appear, from the top of the spectrum?

    • Red, orange, yellow, green, blue, indigo, violet
    • Blue, green, yellow, orange, red, violet, indigo, which mixes up the order of the colours badly
    • Violet, indigo, blue, green, yellow, orange, red, which reverses the usual order of the rainbow
    • Yellow, red, green, violet, blue, indigo, orange, which moves the colours around at random

  8. What does a prism do to a beam of light?

    • It refracts the light, separating its colours by different amounts.
    • It absorbs all the colours and gives off heat, which is why prisms feel warm to the touch.
    • It reflects the light straight back to its source, which is why prisms look like mirrors.
    • It turns the light into sound, which is then heard by the viewer as a faint sound of light.

  9. Why does a rainbow show a spread of colours?

    • The rain paints the sky with coloured dyes that are carried in the falling drops of water.
    • Raindrops act like tiny prisms that separate white sunlight into its colours.
    • The rain absorbs all colours except red, which is why the only colour left in the sky is red.
    • Sunlight is coloured before it reaches the rain, which is why the colours appear as the drops fall.

  10. What is differential absorption?

    • When a material emits a single colour of light, which is why it appears brightly coloured in the dark.
    • When a material absorbs all colours equally, which makes the material look black in all light.
    • When a material refracts light into a spectrum, which spreads its colours out across the surface.
    • When a material absorbs some colours more than others, so it looks coloured.

  11. A green leaf is viewed in green light. What colour does it appear?

    • White, because the green light mixes with the leaf's own colour to give a bright white
    • Green
    • Black, because the leaf absorbs all of the green light that falls on it from the source
    • Red, because green light changes into red when it strikes the surface of the leaf

  12. Which colour appears at the top of the rainbow?

    • Violet, which is refracted the most in raindrops and so appears at the top of the bow
    • Yellow, which is the brightest colour in the rainbow and therefore appears highest in the sky
    • Red
    • Blue, which is the middle colour of the visible spectrum and so lies at the top of the bow

  13. Why does a white shirt look white in sunlight?

    • It refracts all light out of the fabric, which means that little light is left to be seen.
    • It absorbs all colours of light equally, which is why the shirt looks bright in sunlight.
    • It emits white light from its fibres, which makes the cloth glow faintly in the sun.
    • It reflects all colours of light equally.

  14. What do we call the band of colours produced when white light is split?

    • A spectrum
    • A shadow, which is the dark area behind an object that blocks light from a source
    • A diffraction pattern, which is formed when waves spread out through a narrow gap
    • An echo, which is the reflected sound that returns to the listener after a short delay

  15. Which colours of white light are present in equal intensity?

    • Red is the most intense and violet is missing from white light altogether, which is why it looks warm.
    • All the visible colours are present in roughly equal intensity in white light.
    • Only green is present and the other colours are absent, which is why white light looks green.
    • Violet is the most intense and red is missing from white light, which is why it looks cool and blue.

  16. A coloured filter lets only blue light through. What colour does a white object appear when it is viewed through the filter?

    • Blue
    • Black, because the filter stops all of the light from reaching the eye of the viewer
    • White, because the filter adds white light to the object so that it looks white again
    • Red, because the filter turns the blue light into red light before it reaches the eye

  17. Why do colours of objects change in different lighting?

    • The light changes the object's chemical composition, which alters the colour it reflects.
    • The light source may lack the colours the object needs to reflect.
    • The eye stops seeing colour in all lighting conditions, so every object appears grey instead.
    • The object changes its own colour depending on the light, so its surface reacts to the light.

  18. Which statement about diffuse reflection of colour is correct?

    • Diffuse reflection of coloured light from a rough surface makes the colour visible from many directions.
    • Diffuse reflection removes the colour from the light altogether, which leaves the surface colourless.
    • Diffuse reflection only works from smooth mirrors, which are the only surfaces to reflect colour at all.
    • Diffuse reflection turns the colour into a sound, which is then heard by the viewer rather than seen.

  19. Why is a prism able to separate light but a flat sheet of glass is not?

    • The prism stores colours inside it for later use, which is then released as a spectrum.
    • The flat sheet of glass absorbs all colours, which is why it cannot split light into colours.
    • The prism's angled faces refract each colour by a different amount.
    • The prism is a mirror and reflects every colour in one direction, which keeps them together.

  20. Which of these describes what a spectrum shows?

    • The colours of light arranged in order of their frequency.
    • The speed of light in each colour as it passes through a glass block of a fixed thickness
    • The brightness of each colour as it is absorbed by a surface that the light falls onto
    • The number of photons that hit a surface each second as light reaches it from a source

All KS3 Physics quizzes