This exam tips covers Exam Tips 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 13 of 14 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Topic position
Section 13 of 14
Practice
13 questions
Recall
15 flashcards
💡 Exam Tips
🎯 Common Question Types:
- Complete a ray diagram for a convex lens (3 marks)
- Describe the image formed in terms of type, orientation, and size (3 marks)
- Calculate magnification from image/object heights (2 marks)
- Explain how lenses correct vision problems (Higher, 4 marks)
📝 Key Command Words:
- Draw: Show three rays correctly with arrows, mark image position
- Describe: State real/virtual, upright/inverted, magnified/diminished
- Explain: Describe what the lens does to the ray and why (refraction)
- Calculate: image height ÷ object height, no units needed
⚠️ Common Mistakes to Avoid:
- Forgetting to draw arrows on ray diagram lines (marks deducted)
- Giving only one characteristic when "describe" asks for the image (always give all three)
- Saying virtual images cannot be seen — they CAN be seen, just not projected
- Confusing convex (converging) with concave (diverging)
Quick Check: What type of lens would you use to correct short-sightedness, and why?
A concave (diverging) lens. In short-sightedness, the eye lens is too powerful and focuses images in front of the retina. A concave lens diverges the light rays before they enter the eye, reducing the effective power of the optical system so the image is focused correctly on the retina.