CAIE IGCSE Physics: Lens Axis, Focus & Focal Length Question Bank
Practise naming key lens features so ray diagrams use focal length, principal axis and principal focus consistently and accurately.
- Syllabus
- 2026–2028
- Course
- Physics 0625
Practise naming key lens features so ray diagrams use focal length, principal axis and principal focus consistently and accurately.
Fig. 6.1 is a full-size diagram of a lens and an image I of an object.

Fig. 6.1
The focal length of the lens is 3.0 cm .
On Fig. 6.1, mark two points with labels F , to show the positions of the principal focuses (focal points) of the lens.
two points labelled F on principal axis, both 3.0 cm from the centre of the lens
B1