AQA GCSE Physics Physics Paper 2 (Higher), June 2023: Question 4
12 marks · Standard Demand difficulty · Short Answer
Answer questions about loudspeakers, microphones, magnetic fields, induced magnetism, motor effect calculations involving current, force, length and magnetic flux density, and wave frequency data comparison.
Practise this questionQuestion
Question text
04 A megaphone uses a loudspeaker to amplify sounds that are detected by
a microphone.
Figure 10 shows a megaphone and microphone.
Figure 10
04.1 Complete the sentence.
[1 mark]
The microphone is used to convert the pressure variations in sound waves into
variations in .
04.2 The loudspeaker contains a permanent magnet.
Which diagram in Figure 11 shows the direction of the magnetic field between the
north pole and the south pole of the magnet?
The magnets are shown in cross-section.
[1 mark]
Tick ( ) one box.
Figure 11
04.3 Some magnets are permanent magnets and some are induced magnets.
What is an induced magnet?
[1 mark]
Figure 12 shows the parts of the loudspeaker in the megaphone.
Figure 12
A current in the coil of the loudspeaker causes the coil to move.
04.4 What is the name of the effect that causes the coil to move?
[1 mark]
Tick ( ) one box.
Electromagnet effect
Induction effect
Motor effect
Speaker effect 21
04.5 When the current in the coil is 16 mA, the force on the coil is 0.013 N.
The length of the wire that makes up the coil is 6.5 m.
Calculate the magnetic flux density around the coil in the electromagnet.
Use the Physics Equations Sheet.
[4 marks]
Magnetic flux density =22
T
04.6 Megaphones can produce very loud sounds.
A person’s hearing can be affected by age and by working in a loud environment.
Figure 13 shows how frequency affects the minimum sound level that can be heard
by three different people, A, B and C.
Figure 13
Compare how different factors affect the minimum sound level that these
people can hear.
[4 marks]
Mark scheme
Show the mark scheme
Question 4
AO /
Question Answers Extra information Mark
Spec. Ref.
04.1 current allow charge flow 1 AO1
4.7.3.3
or
potential difference
AO /
Spec. Ref.
04.2 1 AO1
4.7.1.2
AO /
Spec. Ref.
04.3 an induced magnet is a material allow ‘when close to another 1 AO1
that becomes a magnet when it magnet’ for ‘when it is placed in 4.7.1.1
is placed in a magnetic field a magnetic field’
or
an induced magnet loses most / allow ‘no magnets are nearby’
all of its magnetism (quickly) for ‘removed from a magnetic
when removed from a magnetic field’
field
‘temporary magnet’ alone is–HYSICS – 8463/2H –
insufficient
AO /
Spec. Ref.
04.4 motor effect 1 AO1
4.7.2.2
4.7.2.4
AO /
Spec. Ref.
04.5 16 mA = 0.016 A allow 1.6 × 10-2 (A) 1 AO2
4.7.2.2
0.013 = B × 0.016 × 6.5 allow correct substitution using 1
incorrectly / not converted
current
0.013 allow correct re-arrangement 1
B = using incorrectly / not converted
0.016 × 6.5
current
allow correct calculation using 1
B = 0.125 (T) incorrectly / not converted
current
allow 0.13 (T)– HYSICS – –
AO /
Question Answers Mark
Spec. Ref.
Level 2: Scientifically relevant features are identified; the way(s) in 3-4 AO3
04.6 which they are similar / different is made clear and (where
4.6.1.4
appropriate) the magnitude of the similarity / difference is noted.
Level 1: Relevant features are identified and differences noted. 1-2
No relevant content 0
Indicative content:
• for all three people, the minimum sound level that can be heard
increases as frequency increases
Age
• the minimum sound level that can be heard increases with age
• between 2000 and 3000 Hz the minimum sound level that can be
heard increases more in B compared to C
• C has very little variation in the minimum sound level that can be
heard at all frequencies
Working in a loud environment:
• increases the minimum sound level that can be heard at all 15
frequencies above 2000 Hz compared to working in a quiet
environment
• the minimum sound level that can be heard increases more as
frequency increases from 2000 to 4000 Hz compared to working
in a quiet environment
• doesn’t affect the minimum sound level that can be heard at
2000 Hz
to access level 2 the answer must include at least one comparison
for age and one comparison for working in a loud environment,
using supporting data/information from the graph
Total Question 4 12
How to answer it
Megaphones, Microphones and Electromagnetism Study Guide
What this question tests
This question covers essential topics from GCSE Physics: Forces and Magnetic Fields (magnets, induced magnetism, motor effect, and magnetic flux density calculations) and Waves (interpreting graphical data regarding hearing, age, and environmental sound levels).
Microphone Energy Transfers
✅ Correct Answer
current (or charge flow) / potential difference
💡 Key Knowledge
- Microphones convert sound waves (pressure variations) into electrical signals.
- A diaphragm vibrates when hit by sound waves, moving a coil of wire relative to a permanent magnet, inducing a potential difference and current.
Magnetic Field Directions
✅ Correct Answer
The diagram showing magnetic field lines pointing out of the North pole and curving towards the South poles (specifically, arrows pointing downwards from top S to central N, and upwards from bottom S to central N).
🧠 Exam Technique
Remember the golden rule of magnetic field lines: they always point from North to South outside the magnet.
Defining an Induced Magnet
✅ Correct Answer
A material that becomes a magnet when it is placed in a magnetic field, and loses most/all of its magnetism quickly when removed from the magnetic field.
❌ Common Errors
Writing just "temporary magnet" is insufficient for the mark. You must explicitly state that it gains magnetism inside a magnetic field and loses it when removed.
The Effect Causing Speaker Movement
✅ Correct Answer
Motor effect
💡 Key Knowledge
When a current flows through a wire placed in a magnetic field, a force is exerted on the wire. This is known as the motor effect.
Calculating Magnetic Flux Density
📐 Step-by-Step Calculation
- Identify the equation: F = B × I × l (Force = Magnetic Flux Density × Current × Length)
- Convert units: Current must be in amperes (A).
16 mA = 16 ÷ 1000 = 0.016 A (or 1.6 × 10⁻² A ) - Rearrange the equation:
B = F / (I × l) - Substitute values:
B = 0.013 / (0.016 × 6.5) - Calculate final answer:
B = 0.125 T (accept 0.13 T )
❌ Common Calculation Traps
Forgetting to convert milliamps (mA) to amps (A) is the #1 place students lose marks here. Always check your prefixes!
Comparing Hearing Ability Graphs
✅ Correct Answer (Level 2 Response)
To score full marks (3–4 marks), you must compare both age and working environment using data from Figure 13:
- General trend: For all people, the minimum sound level that can be heard increases as frequency increases.
- Age comparison (A vs C): Both are 50 (A) vs 25 (C) in loud/quiet environments, but comparing A and B (both 50-year-olds): the older person or person working in a loud environment requires a higher sound level to hear. C (25-year-old) has very little variation in minimum sound level across all frequencies.
- Work environment comparison (A vs B): Working in a loud environment (person A) significantly increases the minimum sound level required to hear across all frequencies above 2000 Hz compared to working in a quiet environment (person B).
🧠 Exam Technique for Extended Writing
This is a Level of Response question. To hit Level 2, your answer must include at least one comparison for age AND one comparison for working environment, backed up with specific data points (frequencies or sound levels) from the graph axes.
Topics
Physics · P6: Waves · P7: Magnetism and Electromagnetism
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.