AQA GCSE Combined Science: Trilogy Physics Paper 2 (Higher), 2024: Question 1

8 marks · Standard Demand difficulty · Short Answer

Investigate how frequency affects the wavelength of a wave on a string, identify the wave equation linking speed, frequency and wavelength, and calculate wavelength from given wave speed and frequency.

Practise this question

Question

The question page shows a waves-on-a-string experiment. A diagram labelled Figure 1 shows a string passing over a pulley with hanging masses to provide tension, stretched horizontally across a bench with a movable wooden bridge, a metre rule underneath, a vibration generator attached at one end, and a signal generator display reading 45.0; the string is drawn in two extreme positions and a double-headed arrow marks one wavelength. The text says a teacher demonstrated how the frequency of a wave on a string affects wavelength, then asks in 01.1 for a method to investigate how frequency affects wavelength using the apparatus shown for 4 marks. Question 01.2 asks which equation links frequency f, wavelength lambda and wave speed v, with three tick-box options: f = lambda × v, lambda = f × v, and v = f × lambda. Question 01.3 states the wave has frequency 45.0 Hz and speed 35.1 m/s and asks students to calculate the wavelength for 3 marks, with answer lines and a final blank labelled 'Wavelength = ... m'.
Question text

01 A teacher demonstrated how the frequency of a wave on a string affects the

wavelength of the wave.

Figure 1 shows the equipment used.

Figure 1

The frequency of the signal generator is adjusted so that the wave shown

in Figure 1 is seen.

At this frequency the string vibrates between the two positions shown in Figure 1.

01.1 Describe a method the teacher could use to investigate how the

frequency of the wave affects the wavelength.

[4 marks]

Use the Physics Equations Sheet to answer questions 01.2 and 01.3.

01.2 Which equation links frequency (f), wavelength (λ) and wave speed (v)?

[1 mark]

*03* Tick ( ) one box.

f = λ × v

λ = f × v

v = f × λ

01.3 The wave on the string has a frequency of 45.0 Hz.

The wave speed is 35.1 m/s.

Calculate the wavelength of the wave.

[3 marks]

Wavelength = m

Mark scheme

Show the mark scheme The mark scheme is presented in tables for questions 01.1 to 01.3. For 01.1, a level-of-response scheme awards 3–4 marks for a valid, logically sequenced method and 1–2 marks for partially relevant steps; indicative points include adjusting the frequency with the signal generator, keeping the number of masses the same, moving the wooden bridge, observing a steady or stationary wave, measuring wavelength with the metre rule, and repeating for different frequencies or stationary wave patterns. For 01.2, the correct answer is v = f × lambda for 1 mark. For 01.3, marks are awarded for substituting into 35.1 = 45.0 × lambda, rearranging to lambda = 35.1 / 45.0, and giving lambda = 0.78 m, with 0.780 also accepted; the total for Question 1 is 8 marks.

AO /

Question Answers Mark

Spec. Ref.

01.1 Level 2: The method would lead to the production of a valid 3–4 AO1

outcome. The key steps are identified and logically sequenced. 6.6.1.2

RPA20

Level 1: The method would not lead to a valid outcome. Some 1–2

relevant steps are identified, but links are not made clear.

No relevant content 0

Indicative content

• use the signal generator to adjust the frequency

• keep the number of masses the same

• move the wooden bridge

• observe a steady / stationary wave pattern

• use the metre rule to measure the wavelength

• repeat using different values of frequency

• repeat for different stationary wave patterns

AO /

Question Answers Extra information Mark

Spec. Ref.

01.2 v = f × λ 1 AO1

6.6.1.2

AO /

Spec. Ref.

01.3 35.1 = 45.0 × λ 1 AO2

6.6.1.2

35.1

λ = 1

45.0

λ = 0.78 allow 0.780 1

Total Question 1 8

How to answer it

Wave frequency and wavelength on a string

What this question tests

Using a string wave experiment, linking frequency, wavelength and wave speed, describing a fair method, and rearranging v = f × λ to calculate wavelength.

Question overview

💡 Key knowledge

  • Frequency is measured in hertz (Hz).
  • Wavelength is the distance between two matching points on a wave.
  • Wave speed, frequency and wavelength are linked by v = f × λ .

🧠 Exam technique

  • For method questions, include enough steps for a fair test.
  • For calculations, write the equation, substitute numbers, then rearrange.
  • Always include units in the final answer.

❌ Common errors

  • Using the wrong equation, such as f = v × λ .
  • Forgetting to keep other variables the same in the experiment.
  • Giving no unit or the wrong unit for wavelength.

Part (a) / 01.1

Describe a method the teacher could use to investigate how frequency affects wavelength. [4 marks]

✅ Correct answer

A full-mark answer should say something like:

Use the signal generator to change the frequency of the wave. Keep the number of masses the same so the tension stays constant. Move the wooden bridge if needed until a steady stationary wave pattern is seen. Measure the wavelength using the metre rule. Repeat for different frequencies and record how the wavelength changes.

💡 Key knowledge

  • The experiment is about changing frequency and observing the effect on wavelength.
  • The tension must stay the same so only frequency is being tested.
  • A stationary wave gives a clear pattern that can be measured properly.

🧠 How marks are awarded

Examiners are looking for linked steps, not just random statements.

  • 1 mark for changing the frequency.
  • 1 mark for keeping the tension constant, e.g. same masses.
  • 1 mark for obtaining a clear/steady wave pattern and measuring wavelength.
  • 1 mark for repeating with different frequencies or different stationary wave patterns.

❌ Common errors

  • Only saying “change the frequency” without explaining how to measure wavelength.
  • Not mentioning keeping the masses the same.
  • Talking about “amplitude” instead of wavelength.
  • Not making it clear that the wave pattern should be steady/stationary.

🧠 Top-level response tip

The best answers were logical and methodical. They described what to change, what to keep the same, what to observe, and how to measure. This is what pushes an answer into the top level for a 4-mark method question.

Part (b) / 01.2

Which equation links frequency (f), wavelength (λ) and wave speed (v)? [1 mark]

✅ Correct answer

v = f × λ

💡 Key knowledge

This is the standard wave equation:

  • v = wave speed
  • f = frequency
  • λ = wavelength

❌ Common errors

  • Choosing f = λ × v or λ = f × v .
  • Mixing up which quantity is being calculated.

Part (c) / 01.3

The wave has frequency 45.0 Hz and wave speed 35.1 m/s. Calculate the wavelength. [3 marks]

📐 Calculation: step-by-step

  1. Write the equation: v = f × λ
  2. Rearrange to make wavelength the subject: λ = v ÷ f
  3. Substitute the numbers: λ = 35.1 ÷ 45.0
  4. Calculate: λ = 0.78 m

Final answer: 0.78 m
Accept 0.780 as well.

💡 Key knowledge

  • Speed is measured in m/s.
  • Frequency is measured in Hz.
  • Wavelength is measured in m.
  • Using the equation correctly shows you understand the relationship between the three quantities.

🧠 Exam technique

  • Show rearrangement to score method marks.
  • Use the given values exactly: 35.1 and 45.0 .
  • Give the answer to an appropriate number of decimal places/significant figures.

❌ Common traps

  • Using λ = f ÷ v instead of λ = v ÷ f .
  • Forgetting the unit: the answer must be in m.
  • Writing 0.7 m without working when the question is worth 3 marks.
  • Rounding too early and losing accuracy.

✅ Mark breakdown for 01.3

  • 1 mark for using the correct equation or rearranged form.
  • 1 mark for correct substitution: 35.1 = 45.0 × λ or equivalent.
  • 1 mark for correct answer: 0.78 m (accept 0.780 ).

Quick revision summary

💡 Remember

Wave equation: v = f × λ

To investigate wavelength: change frequency, keep tension the same, measure wavelength, repeat.

🧠 What examiners want

Clear steps, correct physics words, and a full calculation with units.

❌ Biggest mistake

Not controlling the tension in the method, which means the investigation is not fair.

Topics

Physics · Required Practicals · P6: Waves · Physics Required Practicals

Question and mark scheme from the AQA GCSE Combined Science: Trilogy examination, Physics Paper 2 (Higher), 2024. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.