White light passes through filter P, reflects from an opaque surface and then passes through filter Q to an observer. The table shows the colours each stage transmits or reflects. All other colours are absorbed.
| Stage | Colours transmitted or reflected |
|---|---|
| Filter P | red and green |
| Surface | green and blue |
| Filter Q | red and blue |
Which describes the light reaching the observer?
red light reaches the observer
green light reaches the observer
blue light reaches the observer
no light reaches the observer
93 exam-style questions on Edexcel GCSE Physics 5.1 Reflection, refraction and lenses, covering 5.1.1 Reflection, refraction and total internal reflection, 5.1.2 Specular and diffuse reflection, 5.1.3 Colour of light: absorption and filters, 5.1.4 Lenses: power, focal length and shape, 5.1.5 Ray diagrams for converging and diverging lenses, and 5.1.6 Real and virtual images. Each one has a worked solution and a mark scheme showing where the marks go.