How to draw ray diagrams for convex/converging lenses GCSE Physics Revision

To draw an accurate ray diagram to figure out where the image will be formed, you need to follow these three rules:

1. Draw a ray from the top of the object that goes parallel to the principal axis (the line going horizontally through the centre of the lens). When the ray hits the lens, it then changes direction and passes through the focal point on the other side of the lens.

2. Draw a second ray that goes straight from the top of the object diagonally through the centre of the lens without changing direction.

3. Draw a third ray that passes from the top of the object, through the focal point on the left hand side of the lens and then changes direction when it hits the lens so that it travels parallel to the principal axis (straight line going through the middle) on the other side.