AQA GCSE Physics Physics Paper 2 (Foundation), November 2021: Question 3
10 marks · Standard Demand difficulty · Short Answer
Investigate infrared absorption by different surface colors using flasks, a heater, and thermometers, including identifying an anomalous result, calculating a mean, and drawing conclusions.
Practise this questionQuestion
Question text
03 There are different groups of waves in the electromagnetic spectrum.
03.1 Figure 8 shows the position of three groups of the waves.
Figure 8
Which letter shows the position of infrared?
[1 mark]
Tick ( ) one box.
A B 14C D
A student investigated how the colour of a surface affects the amount of infrared the
surface absorbs.
Figure 9 shows the equipment used.
Figure 9
*0133.*2 Complete the sentence.
Choose the answer from the box.
[1 mark]
a control the dependent the independent
In this investigation the distance between each flask and the infrared heater
is variable.
03.3 The student wrote the hypothesis:
‘Surface colour of the flask affects the amount of infrared
absorbed when the heater is switched on for five minutes.’
Describe how the equipment in Figure 9 could be used to test this hypothesis.
[4 marks]
Table 1 shows the results.
Table 1
Temperature increase in °C
Colour of
*15* flask
Test 1 Test 2 Test 3
Black 19 17 27
Silver 10 12 11
03.4 Which one of the results for the black flask is anomalous?
[1 mark]
03.5 The anomalous result was caused by reading the thermometer incorrectly.
What should the student do with the anomalous result?
[1 mark]
03.6 Calculate the mean temperature increase for the silver flask.
[1 mark]
Mean temperature increase = °C
03.7 What conclusion can be made from Table 1?
[1 mark]
Tick ( ) one box.
Both flasks absorbed the same amount of infrared during the five minutes.
*16* The black flask absorbed the most infrared during the five minutes.
The silver flask absorbed the most infrared during the five minutes.
Mark scheme
Show the mark scheme
Question 3
AO /
Question Answers Extra information Mark
Spec. Ref.
03.1 B 1 AO1
4.6.2.1
03.2 a control 1 AO1
4.6.2.2
RPA10
03.3 record the initial temperature of allow initial temperature is a 1 AO1
the two thermometers in each control variable 4.6.2.2
flask or RPA10
ensure initial temperature is the
same in both flasks
switch the infrared heater on allow switch on the power 1
and start the stop clock (at the supply for switch on the heater
same time)
after five minutes record the allow calculate the temperature 1
(final) temperature from both increase / change after five
flasks minutes
see / check if the temperature 1
inside the flasks had increased
by different amounts
03.4 27 (°C) allow 27 (°C) identified on the 1 AO3
table 4.6.2.2
allow test 3 RPA10
03.5 ignore (the result) allow repeat (the result) 1 AO1
4.6.2.2
RPA10
03.6 (33/3 = ) 11 1 AO2
4.6.2.2
RPA10
03.7 the black flask absorbed the 1 AO3
most infrared during the five 4.6.2.2
minutes RPA10
Total 10
How to answer it
Electromagnetic Waves & Infrared Radiation Investigation
What this question tests
This question assesses your knowledge of the electromagnetic spectrum order, identifying control variables in practical investigations, describing methods for required practicals (RPA10: Infrared radiation absorption/emission), handling anomalous data, calculating means, and drawing conclusions from experimental data.
The Electromagnetic Spectrum Position
✅ Correct Answer
Letter B
💡 Key Knowledge
- Order of the EM spectrum (low to high frequency): Radio waves, Microwaves, Infrared, Visible light, Ultraviolet, X-rays, Gamma rays.
- Infrared sits directly between microwaves and visible light.
Identifying Variables
✅ Correct Answer
a control variable
🧠 Exam Technique
When asked about distance, temperature at start, or volume in practicals where you are changing one thing (colour) to see the effect on another (temperature rise), keep everything else identical. This makes it a control variable.
Describing a Practical Procedure
✅ Correct Answer
A 4-step sequential description is required:
- Record initial temperature of both thermometers.
- Switch on the infrared heater and start the stop clock simultaneously.
- Record final temperature after 5 minutes (or calculate temperature change).
- Check/compare if the temperature increased by different amounts.
❌ Common Errors
Students often lose marks by forgetting to state that initial temperatures must be checked/recorded to ensure they start at the same baseline, or by missing the instruction to use a stop clock simultaneously with the heater.
Identifying Anomalous Results
✅ Correct Answer
27 (°C) (or Test 3 for the black flask)
🧠 Exam Technique
Scan across rows looking for values that do not fit the general pattern. While Test 1 is 19 and Test 2 is 17, Test 3 jumps up to 27, making it an outlier (anomaly) compared to the others.
Dealing with Anomalous Results
✅ Correct Answer
Ignore the result (or repeat the result/test)
💡 Key Knowledge
Standard scientific procedure for handling identified anomalies during calculations is to discard them before calculating a mean, or to repeat the measurement if possible.
Calculating a Mean
📐 Step-by-Step Calculation
- Identify data for the silver flask: 10, 12, 11.
- Add them together: 10 + 12 + 11 = 33.
- Divide by the number of valid tests (3): 33 ÷ 3 = 11.
Mean temperature increase = 11 °C
❌ Common Calculation Traps
Do not accidentally include the anomalous black flask data here. Ensure you divide by 3, not 2.
Drawing Conclusions
✅ Correct Answer
Tick: The black flask absorbed the most infrared during the five minutes.
💡 Key Knowledge
Matt, dark surfaces are much better absorbers (and emitters) of infrared radiation compared to light, shiny, or silver surfaces, which reflect most infrared radiation.
Topics
Physics · Required Practicals · P6: Waves · Required Practicals
Question and mark scheme from the AQA GCSE Physics examination, Physics Paper 2 (Foundation), November 2021. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.