AQA GCSE Physics Physics Paper 2 (Higher), June 2023: Question 7
10 marks · Standard Demand difficulty · Short Answer
Investigate reflection and refraction of light including types of reflection, conclusions from data, errors, and wavefront behavior at boundaries.
Practise this questionQuestion
Question text
07 A student investigated the behaviour of light.
The student used a mirror with a smooth surface to investigate reflection.
Figure 17 shows the equipment used.
Figure 17
07.1 What name is given to reflection from a smooth surface?
[1 mark]
The student measured the angle of reflection for different angles of incidence.
Table 2 shows the results.
Table 2
Angle of Angle of reflection in degrees
incidence in
degrees Test 1 Test 2 Test 3 Mean
10 8 10 11 10
20 20 21 20 20
30 28 29 32 30
40 39 41 41 40
50 49 50 52 50
07.2 What conclusion can be made from the results in Table 2?
[1 mark]
07.3 What type of error caused the variation in the results for the angle of reflection?
Suggest one cause of this error.
[2 marks]
Type of error
Cause of error
The student also investigated the refraction of light.
07.4 Figure 18 shows the path of a ray of light through a glass block.
*31* Figure 18
Why has refraction not occurred?
[1 mark]
07.5 The student measured the angle of refraction for different angles of incidence.
Figure 19 shows the protractor used.
Figure 19
When the angle of incidence was 10° the student measured the angle of refraction
four times.
*32* The student recorded the measurements as:
6.0° 6.3° 6.4° 5.8°
Explain why the student should not have recorded these results when using the
protractor in Figure 19 to make the measurements.
[2 marks]
07.6 Figure 20 shows what happens to wave fronts as they pass across the boundary
between air and glass.
Figure 20
Explain in terms of the wave fronts, why refraction happens at the boundary between
air and glass.
[3 marks]
Mark scheme
Show the mark scheme
Question 7
AO /
Question Answers Extra information Mark
Spec. Ref.
07.1 specular (reflection) 1 AO1
4.6.2.6
AO /
Spec. Ref.
07.2 the angle of incidence = the 1 AO3
4.6.1.3
(mean) angle of reflection
RPA9
AO /
Spec. Ref.
07.3 random 1 AO3
4.6.1.3
RPA9
any one from: 1
• the student’s eye / head might allow parallax
not be in the same position
each time
• the centre of the ray may not
have been marked correctly
• the mirror / ray box may not allow protractor not in the
have been (re)placed correct position
correctly
incorrect measurement of the
angle(s) is insufficient
AO /
Spec. Ref.
07.4 all points on a wavefront enter allow incident ray (of light) is 1 AO1
4.6.1.3
the glass at the same time along the normal– HYSICS – –
RPA9
AO /
Spec. Ref.
07.5 the resolution (of the protractor) 1 AO3
4.6.1.3
is 1(°)
RPA9
(so) could not be used to allow (so) could not be used to 1
measure the difference between measure to 1 decimal place 21
the results
AO /
Spec. Ref.
07.6 different parts of the wavefront 1 AO1
4.6.2.2
enter the glass at different times
the velocity / speed (of light) is 1
less in glass
(so) one part of the wave front 1
changes speed before other
parts
Total Question 7 10
How to answer it
Investigation of Reflection and Refraction of Light
What this question tests
This question assesses your understanding of light reflection and refraction required practicals. It tests key recall of wave terms (specular reflection), analyzing experimental data, identifying experimental errors (random errors and resolution limits), and explaining wave behavior at boundaries using wavefronts and changes in speed.
Specular Reflection
✅ Correct Answer
Specular (reflection)
💡 Key Knowledge
Reflection from a smooth, flat surface (like a mirror) is called specular reflection, where parallel rays are reflected in a single direction. This contrasts with diffuse reflection from rough surfaces.
Analyzing Experimental Data & Conclusions
✅ Correct Answer
The angle of incidence = the (mean) angle of reflection.
🧠 Exam Technique
When asked for a conclusion from a table of results, look for patterns or mathematical relationships between the independent variable (angle of incidence) and the dependent variable (mean angle of reflection). Here, the numbers are identical.
Types of Experimental Errors
✅ Correct Answer
Type of error: Random (error)
Cause of error (any one):
- The student's eye/head might not be in the same position each time (Parallax).
- The centre of the ray may not have been marked correctly.
- The mirror / ray box may not have been (re)placed correctly.
❌ Common Errors
Students often write "human error". Examiners do not accept this vague term—you must state the specific source of the variation, such as parallax or positioning of equipment.
Refraction and Wavefronts (Normal Incidence)
✅ Correct Answer
All points on a wavefront enter the glass at the same time.
Alternative: Incident ray of light is along the normal.
💡 Key Knowledge
Refraction only happens when a wave changes speed. If light hits a boundary straight on (along the normal), every part of the wavefront crosses the boundary simultaneously, so no part slows down before the rest.
Instrument Resolution and Decimals
✅ Correct Answer
The resolution (of the protractor) is 1 degree (1°).
(So) it could not be used to measure the differences between the results (which are given to 1 decimal place / fractions of a degree).
🧠 Exam Technique
Always inspect the scale of measuring instruments shown in diagrams. A standard protractor only has markings every 1°, meaning it is physically impossible to reliably measure values like 6.3° without guessing.
Explaining Refraction Using Wavefronts
✅ Correct Answer
- Different parts of the wavefront enter the glass at different times.
- The velocity/speed of light is less in glass (than in air).
- (So) one part of the wavefront changes speed before other parts, causing the wave to change direction (bend).
💡 Key Knowledge
This is a standard 3-mark explanation sequence for wave refraction. Memorize the logical chain: Time difference at boundary → Speed difference in medium → Differential slowing causing a change in direction.
Topics
Physics · Required Practicals · P6: Waves · Required Practicals
Question and mark scheme from the AQA GCSE Physics examination, Physics Paper 2 (Higher), June 2023. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.