AQA GCSE Physics Physics Paper 2 (Foundation), June 2023: Question 8
8 marks · Standard Demand difficulty · Short Answer
Analyze lenses including identifying focal points, completing ray diagrams for concave lenses, comparing image properties of convex and concave lenses, and calculating magnification and image height.
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Question text
08 Lenses can be used to form an image of an object.
08.1 Figure 20 shows parallel rays of light being refracted by a convex lens.
Figure 20
What is the position marked ‘F’ called?
[1 mark]
Tick ( ) one box.
Focal length
Focus point
Principal focus 33
08.2 Complete the ray diagram in Figure 21 to show how a concave lens forms the image
of the object.
Use an arrow to represent the image.
[2 marks]
Figure 21
08.3 Figure 22 shows how a convex lens can be used to form a magnified image of
an object.
Figure 22
Give two ways that the image formed by the convex lens in Figure 22 is similar to the
image formed by the concave lens.
[2 marks]
08.4 A convex lens is used as a magnifying glass to identify a symbol on the back of a
silver spoon.
*33* The symbol has an actual height of 1.6 mm.
The magnification produced by the lens is 3.5
Calculate the image height of the symbol when viewed through the magnifying glass.
Use the Physics Equations Sheet.
[3 marks]
Image height = mm
Mark scheme
Show the mark scheme
Question 8
AO /
Question Answers Extra information Mark
Spec. Ref.
08.1 principal focus 1 AO1
4.6.2.5
AO /
Question Answers Mark
Spec. Ref.
08.2 ray through the centre of the lens 1 AO2
4.6.2.5
image in correct position and with correct orientation 1
AO /
Spec. Ref.
08.3 upright allow right way up 1 AO3
4.6.2.5
virtual ignore not real 1
ignore it is on the same side of
the lens
AO /
Spec. Ref.
08.4 image height 1 AO2
3.5 =
1.6 4.6.2.5
image height = 3.5 × 1.6 1
image height = 5.6 (mm) 1
Total Question 8 8
How to answer it
GCSE Physics Study Guide: Lenses & Ray Diagrams
What this question tests
This question assesses your understanding of lenses (both convex and concave), the terminology used for focal points, how to construct and interpret ray diagrams, comparing image properties (upright, virtual, magnified), and applying the magnification equation to solve numerical problems.
Identifying the Focal Point
✅ Correct Answer
Principal focus
💡 Key Knowledge
- When parallel rays of light enter a convex lens, they converge (meet) at a specific point on the axis.
- In AQA physics, the correct scientific terminology for this point is the principal focus.
Ray Diagrams for a Concave Lens
✅ Correct Answers & Mark Breakdown
- Mark 1: A straight line drawn passing directly through the center of the lens without changing direction.
- Mark 2: An upright arrow positioned correctly where the refracted ray (extended backwards) intersects the construction ray from the top of the object.
🧠 Exam Technique
- Always use a sharp pencil and a ruler for ray diagrams.
- Remember the golden rule for lenses: a light ray passing through the exact optical center of a lens continues straight through without refracting.
❌ Common Errors
Students often bend the ray at the center of the lens or forget to add an arrowhead to represent the final orientation of the image.
Comparing Lens Images
✅ Correct Answers
- 1. Upright (accept "right way up")
- 2. Virtual (accept "not real")
💡 Key Knowledge
Both a magnifying glass (convex lens used up close) and a concave lens produce images that are virtual (light rays only appear to diverge from them) and upright compared to the original object.
Magnification Calculation
📐 Step-by-Step Calculation
- State the equation: magnification = image height / object height
- Substitute the values: 3.5 = image height / 1.6
- Rearrange and solve: image height = 3.5 × 1.6
- Final Answer: 5.6 mm
❌ Common Calculation Traps
- Dividing instead of multiplying the numbers.
- Forgetting to check unit consistency (though both are in mm here, always watch out for cm-to-mm conversions in other questions).
Topics
Physics · P6: Waves
Question and mark scheme from the AQA GCSE Physics examination, Physics Paper 2 (Foundation), June 2023. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.