Draw ray diagrams to show the images formed by a convex lens for different positions of the object, and state the nature of each image.

1. 1 · Open in one line. A convex lens converges light; the position and nature of the image depend on where the object is placed.
2. 2 · State the ray rules.
   • A ray parallel to the axis passes through F.
   • A ray through O goes straight on.
   • A ray through F comes out parallel to the axis.
3. 3 · Draw the diagrams. [Diagrams: principal axis, lens, F and 2F on both sides; object beyond 2F, at 2F, between F and 2F, and between F and O; image drawn and labelled in each]
4. 4 · List the results.
   • Beyond 2F: image between F and 2F, real, inverted, diminished.
   • At 2F: image at 2F, real, inverted, same size.
   • Between F and 2F: image beyond 2F, real, inverted, magnified.
   • At F: image at infinity, highly magnified.
   • Between F and O: same side, virtual, erect, magnified.
5. 5 · Real-life link. Camera (beyond 2F), photocopier (at 2F), projector (between F and 2F), magnifying glass (between F and O).
6. 6 · Close in one line. As the object moves closer to F, the real image moves away from the lens and becomes larger.

Scoring tip: Use a ruler and put arrows on every ray. Two rays are enough for each diagram; label F, 2F, O and the image.