1Can you use the lens made from a bottle and water to read small letters in a book or magnify small objects?
2What is a lens? Name two materials a lens can be made from.
3Write three differences between a convex lens and a concave lens.
4Why do most lenses have two centres of curvature? How are they labelled?
5Define optical centre and principal axis.
6Treating a convex lens as a set of prisms, explain why it brings parallel rays together.
7Why is the principal focus of a concave lens described as the point from which rays only appear to diverge?
8A lens has a radius of curvature of 36 cm. Find its focal length.
9Name the three shapes of converging lens and the three shapes of diverging lens.
10Name four devices in which convex lenses are used.