AQA GCSE Combined Science: Trilogy Physics Paper 2 (Foundation), 2023: Question 6

9 marks · Standard Demand difficulty · Short Answer

Identify components of the electromagnetic spectrum, compare wave properties, and calculate wave frequency using the wave equation.

Practise this question

Question

An exam page featuring questions on the electromagnetic spectrum. Figure 14 shows a block diagram of the EM spectrum with missing labels A, B, and C alongside Infrared, Visible light, Ultraviolet, and Gamma rays. Figure 15 depicts a ray of white light entering a triangular glass prism and dispersing into a spectrum of colors: Red, Orange, Yellow, Green, Blue, Indigo, and Violet. The text includes questions on naming EM groups, comparing UV and gamma rays, identifying refraction, and a calculation task for frequency using wave speed and wavelength in standard form.
Question text

06 The Sun emits a continuous spectrum of electromagnetic waves.

Figure 14 names some of the groups of waves in the electromagnetic spectrum.

Figure 14

06.1 Name groups A, B and C in Figure 14.

[2 marks]

A

B

C

06.2 Give one similarity and one difference between the properties of ultraviolet waves and

gamma rays.

[2 marks]

Similarity

Difference

Figure 15 shows white light split into a spectrum of different colours by a glass prism.

Figure 15

06.3 Light changes direction when it enters the glass prism.

What name is given to this process?

[1 mark]

Use the Physics Equations Sheet to answer questions 06.4 and 06.5.

06.4 Write down the equation that links frequency (f), wavelength (λ) and wave speed (v).

[1 mark]

06.5 The wave in the middle of the spectrum has a wavelength of 5.0 × 10–7 m.

wave speed of light = 3.0 × 108 m/s

Calculate the frequency of the wave.

[3 marks]

Frequency = Hz

Mark scheme

Show the mark scheme The mark scheme for question 6. For 06.1, it identifies A as radio waves, B as microwaves, and C as X-rays. For 06.2, it lists similarities such as 'same speed in a vacuum' and differences such as 'gamma has a higher frequency'. 06.3 identifies the process as refraction. 06.4 gives the equation 'wave speed = frequency × wavelength'. 06.5 shows the calculation steps: substituting values into the equation, rearranging to find frequency, and the final result of 6 × 10^14 Hz.

Question 6

AO /

Question Answers Extra information Mark

Spec. Ref.

06.1 A radio waves 2 AO1

6.6.2.1

B microwaves

C X-rays

allow 1 mark if 2 correct

AO /

Spec. Ref.

06.2 Similarity AO1

6.6.2.2

any one from: 1

• same speed (in a vacuum) allow both can travel through a

• both transfer energy vacuum

• both transverse allow both are ionising

allow both can harm living tissue

allow both can be used for

medical treatment / imaging

Difference

any one from:

• gamma has a higher allow gamma has more energy

frequency

• gamma has a shorter

wavelength

• gamma is more ionising

• gamma is more penetrating

AO /

Spec. Ref.

06.3 refraction 1 AO1

– OMBINED SCIENCE: TRILOGY – – 6.6.2.2

AO /

Spec. Ref.

06.4 wave speed = frequency × 1 AO1

wavelength 6.6.1.2

or

v = f λ

AO /

Spec. Ref.

06.5 3.0 × 108 = f × 5.0 × 10–7 1 AO2

6.6.1.2

3.0 × 108 allow a correct rearrangement 1

f = −7 using incorrect powers of 10

5.0 × 10

14 allow a correct calculation of f 1

f = 6 × 10 (Hz)

using incorrect powers of 10

allow 6.0 × 1014 (Hz)

Total Question 6 9

How to answer it

The Electromagnetic Spectrum & Wave Properties

What this question tests

This question assesses your ability to recall the order of the electromagnetic (EM) spectrum, compare the properties of different waves, identify the process of refraction, and perform multi-step wave speed calculations using standard form.

Part 06.1

Ordering the EM Spectrum

Correct Answers

  • A: Radio waves
  • B: Microwaves
  • C: X-rays

2 marks: All 3 correct. (1 mark if 2 correct).

Key Knowledge

The EM spectrum is a continuous range of waves ordered by wavelength or frequency. From longest wavelength to shortest:

Radio → Micro → Infrared → Visible → UV → X-ray → Gamma

Exam Technique

Use a mnemonic to remember the order, such as: Roman Men Invented Very Unusual X-ray Guns.

Part 06.2

Comparing UV and Gamma

Correct Answers

Similarity: Same speed (in a vacuum), both transfer energy, or both are transverse waves.

Difference: Gamma has a higher frequency, shorter wavelength, or is more ionising/penetrating than UV.

Examiner Insight

When asked for a similarity between any two EM waves, the safest answer is always "they travel at the same speed in a vacuum" (3.0 × 10⁸ m/s).

Part 06.3

Light in a Prism

Correct Answer

Refraction

Key Knowledge

Refraction occurs because light changes speed when it moves from one medium (like air) into another (like glass). This causes the light to bend.

Common Error

Don't confuse Refraction (bending) with Reflection (bouncing) or Diffraction (spreading out).

Part 06.4 & 06.5

The Wave Equation Calculation

The Equation

wave speed = frequency × wavelength

In symbols: v = fλ

Step-by-Step Calculation

1. Identify the variables:
Wave speed (v) = 3.0 × 10⁸ m/s
Wavelength (λ) = 5.0 × 10⁻⁷ m

2. Rearrange the equation for frequency (f):
f = v / λ

3. Substitute the values:
f = (3.0 × 10⁸) / (5.0 × 10⁻⁷)

4. Calculate the final answer:
f = 6.0 × 10¹⁴ Hz

Calculation Traps

  • Calculator Error: When dividing by standard form, always use brackets: 3.0E8 / (5.0E-7) .
  • Rearrangement: Students often multiply the two numbers instead of dividing. Use a formula triangle if it helps!

Top Level Response

Even if you get the final number wrong, you get 1 mark for the correct rearrangement and 1 mark for substituting the numbers correctly. Always show your working!

Topics

Physics · P6: Waves

Question and mark scheme from the AQA GCSE Combined Science: Trilogy examination, Physics Paper 2 (Foundation), 2023. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.