Light rays and images
What students will learn
Construct ray models of reflection and refraction and use them to explain where images form.
Before this topic
- Wavefronts and wavelength
- Angles from a normal and basic trigonometry
- Signed reciprocals and similar triangles
Read and connect
Read: Reflection →
Distinguish rays from wavefronts and apply reflection angles to the local normal.
Read: Refraction →
Connect refraction with index, unchanged frequency, and the conditions for total internal reflection.
Read: Images Formed by Mirrors →
Construct mirror images while keeping real paths, extensions, and signed focal lengths distinct.
Read: Images Formed by Lenses →
Use near and far focal points to construct lens images and interpret their distances and magnification.
Check understanding
Use the complete prompt to make student reasoning visible, then consult the separate worked reasoning and criteria. A reading completion tick records reading history.
Construct a lens image →
Calculate the image and signed magnification, then draw all three principal rays and identify the two focal points.
The task uses a thin converging lens in air and the stated sign convention.
Plan and graph a refraction measurement →
Control unwanted curved-face refraction, measure angles from the normal, and use a quantitative sine graph to infer index.
This is procedure design and supplied-data analysis, rather than evidence of completed hands-on measurement.
Standards and earlier reading lists
These topic placements organize reading. Edition-qualified Standards mappings and the existing complete unit task sets retain their reviewed scope.