Unit 3 Properties of waves
Drawing ray diagrams
- For a converging lens, to find the position of an image:
- Draw a ray from the top of the object through the centre of the lens, which does not change direction.
- Draw a ray from the top of the object parallel to the principal axis until it reaches the plane of the lens. The ray then passes straight through the principal focus on the other side of the lens. An image is formed where the rays meet.
- A converging lens can be used as a magnifying glass when an object is placed between F and the lens.