An opaque white seashell is lit by white light. A student looks at the seashell through an ideal blue filter. Which explains why the seashell appears blue?
the filter reflects every colour except blue back towards the seashell
the filter transmits the blue part of the reflected light and absorbs the other colours
the filter adds blue to the white light that is reflected from the seashell
the seashell absorbs every colour in the white light except blue light
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.