Q. 1 Why are electric light bulbs shaped the way they are? (any reasonable answer will be accepted)

Q. 2 One example of how shadows can be used to generate art was by Etienne de Silhouette who used to trace people's silhouettes (hence the name). His big problem was that the small candles he used weren't very bright. Why didn't he simply use a bigger light source in order to get more light?

Q. 3 In the lectures I showed a photograph of an astronaut. His visor allows some light to pass through the visor and some to be reflected. You cannot see the astronaut's face through his visor. Use a ray diagram to explain how he can still see you!

Q. 4 In the lectures I showed a photograph of a "sun pillar" produced by the sun setting over the ocean. Use a ray-tracing diagram to explain why the sun (a spherical light source) produces a stripe-shaped reflection.

Q. 5 An example where an optical trick was used in the theater is "Pepper's Ghost", where J.H. Pepper produced what appeared to a ghostly figure hovering above the stage next to an actor. Draw a ray diagram and explain a possible way that Pepper could have used a sheet of glass to do this (points will be awarded for clarity).

Q. 6 Mirror images show "left to right" reversal, making most words unreadable in a mirror! Write down three words that still make sense when reflected by a plane mirror. The reflected word need not be the same as the original.

Q. 7 In the picture below, two mirrors are positioned perpendicular to each other. When you look at the image of the clock, which way round do the hands rotate? Explain your answer in terms of reflection.