A student draws a ray diagram for a diverging lens. The lens is at x=0x=0x=0 and its foci are at x=−6 cmx=-6\ \mathrm{cm}x=−6 cm and x=+6 cmx=+6\ \mathrm{cm}x=+6 cm. An object is at x=−18 cmx=-18\ \mathrm{cm}x=−18 cm. A ray from its top travels parallel to the principal axis towards the lens. Which construction locates the virtual image?
extend the outgoing ray back through x=+6 cmx=+6\ \mathrm{cm}x=+6 cm and intersect it with the centre ray
extend the outgoing ray back through x=−6 cmx=-6\ \mathrm{cm}x=−6 cm and intersect it with the centre ray
draw the outgoing ray through x=+6 cmx=+6\ \mathrm{cm}x=+6 cm and intersect it with the centre ray
draw the outgoing ray through x=−6 cmx=-6\ \mathrm{cm}x=−6 cm and intersect it with the centre ray
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.