4.6 Waves - light

Unit Summary

Understanding how light behaves is essential for explaining how we see, how images are formed, and how lenses and mirrors work. In AQA GCSE Physics Unit 4.6 Waves, students explore light as a transverse wave, focusing on how it reflects off surfaces, refracts through different media, and forms images through lenses. These lessons provide the foundation for understanding key technologies in optics, photography, and human vision.

This unit is fully aligned with the AQA GCSE Physics specification and builds on prior knowledge of basic wave properties and energy transfer. Students learn how to draw and interpret ray diagrams, investigate how light changes direction when entering different materials, and explore how convex and concave lenses converge or diverge light to form real and virtual images. The concept of refractive index is introduced, along with practical contexts such as prisms, lenses in glasses and cameras, and everyday reflections.

Substantive knowledge (e.g., ray behaviour, angles of incidence and refraction, lens rules) is taught alongside disciplinary knowledge (such as how to plan investigations, measure angles accurately, and evaluate the quality of optical images). Through required practicals—including the investigation of refraction through glass blocks and image formation using lenses—students build confidence applying theoretical knowledge to real-world experiments.

Careful scaffolding and retrieval tasks help students recall prior learning about waves and apply it in new contexts. They develop key scientific skills including drawing and labelling diagrams, interpreting results, and reasoning about the paths of light rays in complex systems.

At Developing Experts, we support schools in delivering the National Curriculum while connecting learning to real-life applications. The study of light is not just abstract—it’s deeply relevant in areas like vision correction, camera design, optical instruments, and scientific research. By understanding how light behaves, students gain insight into how physics explains and shapes the world we see—literally.