(a) With the help of a labelled diagram, explain how a concave lens diverges a beam of parallel light rays. Mark the principal axis, optical centre, principal focus and focal length of the concave lens on the diagram. (b) State whether concave lens has a real focus or a virtual focus. (c) List some things that concave lens and convex mirror have in common.
If two lenses, one convex and concave of equal focal lengths are placed in contact, the parallel incident ray will:
a.pass undeviated b.deviate c.meet at focus of convex lens d.meet at focus of concave lens