This key facts covers Key Terms and the Magnification Equation within Lenses & Images for GCSE Physics. Revise Lenses & Images in Waves for GCSE Physics with 13 exam-style questions and 15 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 6 of 14 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 6 of 14
Practice
13 questions
Recall
15 flashcards
🔑 Key Terms and the Magnification Equation
- Principal axis — the horizontal line through the centre of the lens
- Focal point (F) — where parallel rays converge (convex) or appear to diverge from (concave)
- Focal length (f) — distance from the lens centre to the focal point
- Magnification = image height ÷ object height
Magnification = image height ÷ object height
If magnification > 1, image is larger; if < 1, image is smaller; if = 1, image is same size
Quick Check: An object is 2 cm tall and its image through a lens is 6 cm tall. What is the magnification?
Magnification = image height ÷ object height = 6 ÷ 2 = 3. The image is 3 times larger than the object.