Lenses and Visible Light (Higher Tier)

This lesson covers lenses and visible light — including convex and concave lenses, ray diagrams, and the formation of images — as required by the AQA GCSE Combined Science Trilogy (8464) Higher Tier content, Physics Paper 2, section 6.2. This topic is Higher Tier only — it will not appear on Foundation Tier papers.

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Types of Lenses

There are two types of lens:

Lens type	Shape	Also called	Effect on light
Convex (converging)	Thicker in the middle, thinner at the edges	Converging lens	Brings parallel rays together to a focus
Concave (diverging)	Thinner in the middle, thicker at the edges	Diverging lens	Spreads parallel rays apart (they appear to come from a focus behind the lens)

graph LR
    subgraph "Convex Lens (Converging)"
    direction LR
    A["Parallel rays →"] --> B["Convex lens"]
    B --> C["→ Focus (F)"]
    end

graph LR
    subgraph "Concave Lens (Diverging)"
    direction LR
    D["Parallel rays →"] --> E["Concave lens"]
    E --> F["Rays diverge ← appear to come from F behind lens"]
    end

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Key Terms