A technician inspects two opaque plastic gears. Gear X appears blue and gear Y appears white in white light. An inspection lamp emits only blue light.
The technician first looks directly at the gears and then looks at them through a red filter.
Explain whether the technician can distinguish the gears by colour in each case.
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.