AQA A-LEVEL PHYSICS · 7408
Paper 3
Revision Notes
Practical skills & data analysis · Required practicals · Astrophysics
option
Practical skills and data analysis Required practicals Telescopes
Classifying stars Cosmology
Built from the AQA 7408 specification. Includes worked examples, quick-check questions with
answers, all 12 required practicals, an equation list and an exam checklist. Section B covers
the Astrophysics option.
,Contents
Using this pack 3
Practical skills and data analysis
How Paper 3 Section A works 4
Graphs and data analysis 5
Uncertainties 6
Errors, accuracy and precision 7
Designing and describing experiments 8
Worked examples: data analysis 9
Worked examples: uncertainties 10
Quick check: Section A 11
Required practicals
Required practicals 1 to 6 12
Required practicals 7 to 12 13
Telescopes
Refracting and reflecting telescopes 14
Reflectors vs refractors 15
Resolving power, collecting power, CCDs 16
Worked examples: telescopes 17
Classifying stars
Magnitude: how bright stars look 18
Worked examples: magnitudes 19
Black-body radiation and star temperature 20
Spectral classes 21
The Hertzsprung-Russell diagram 22
Supernovae, neutron stars and black holes 23
Worked examples: stars and black holes 24
Quick check: stars 25
Cosmology
The Doppler effect and red shift 26
Hubble’s law and the Big Bang 27
Quasars 28
Detecting exoplanets 29
Worked examples: cosmology 30
Quick check: cosmology 31
Reference
Equations for Paper 3 32
Exam checklist 33
Paper 3 revision notes · 2
,REFERENCE
Using this pack
How the pack works
Paper 3 is a 2 hour written paper, 80 marks, 32% of the A level. Section A (45
marks, compulsory) tests practical skills and data analysis; Section B (35 marks)
tests one option topic - this pack covers Astrophysics (section 3.9 of the AQA 7408
specification).
If your school teaches a different option (Medical physics, Engineering physics,
Turning points in physics or Electronics), Section A of this pack still applies to you
in full.
Each topic has colour-coded notes, worked examples with every step shown, and
quick-check questions with answers.
The last pages hold the 12 required practicals, an equation list and an exam
checklist. Assumed knowledge from Papers 1 and 2 can appear anywhere.
Constants used in the examples
Gravitational constant G 6.67 × 10⁻¹¹ N m² kg⁻²
Speed of light c 3.00 × 10⁸ m s⁻¹
Stefan constant σ 5.67 × 10⁻⁸ W m⁻² K⁻⁴
Wien constant 2.9 × 10⁻³ m K
Hubble constant H 65 km s⁻¹ Mpc⁻¹
1 parsec 3.08 × 10¹⁶ m (≈ 3.26 light years)
1 light year 9.45 × 10¹⁵ m
1 Mpc 10⁶ pc
Solar mass M☉ 1.99 × 10³⁰ kg
Solar radius R☉ 6.96 × 10⁸ m
1 year ≈ 3.16 × 10⁷ s
Rounding
Carry full calculator values through a calculation and round only the final answer to
the same number of significant figures as the data (usually 2 or 3).
Paper 3 revision notes · 3
, PRACTICAL SKILLS AND DATA ANALYSIS
How Paper 3 Section A works
The paper at a glance
Paper 3 is a 2 hour written exam, 80 marks, 32% of the A level.
Section A (45 marks, compulsory): short and long answer questions on practical
experiments and data analysis. Any of the 12 required practicals can come up,
often in an unfamiliar context.
Section B (35 marks): short and long answer questions on your option topic. This
pack covers Astrophysics (specification section 3.9).
Assumed knowledge from the whole specification can appear in either section.
What the questions are really testing
The examiners call these practical skills PS1 to PS4. In plain words they want you to:
Solve problems in practical contexts - apply physics you know to an experiment
you may never have seen.
Comment on and improve experimental design - variables, control, resolution
of instruments, safety.
Present and analyse data - plot and interpret graphs, process results, use log
graphs.
Evaluate results - judge accuracy and precision, use uncertainties, draw justified
conclusions.
Know the instruments - micrometers, verniers, stopwatches, multimeters,
oscilloscopes, light gates, data loggers.
Command words
Describe/Explain - say what and why, in order. Determine - use the data to get a
value with a unit. Show that - give every step and end with at least one more
significant figure than the target. Evaluate - judge with evidence from the data.
Paper 3 revision notes · 4
Paper 3
Revision Notes
Practical skills & data analysis · Required practicals · Astrophysics
option
Practical skills and data analysis Required practicals Telescopes
Classifying stars Cosmology
Built from the AQA 7408 specification. Includes worked examples, quick-check questions with
answers, all 12 required practicals, an equation list and an exam checklist. Section B covers
the Astrophysics option.
,Contents
Using this pack 3
Practical skills and data analysis
How Paper 3 Section A works 4
Graphs and data analysis 5
Uncertainties 6
Errors, accuracy and precision 7
Designing and describing experiments 8
Worked examples: data analysis 9
Worked examples: uncertainties 10
Quick check: Section A 11
Required practicals
Required practicals 1 to 6 12
Required practicals 7 to 12 13
Telescopes
Refracting and reflecting telescopes 14
Reflectors vs refractors 15
Resolving power, collecting power, CCDs 16
Worked examples: telescopes 17
Classifying stars
Magnitude: how bright stars look 18
Worked examples: magnitudes 19
Black-body radiation and star temperature 20
Spectral classes 21
The Hertzsprung-Russell diagram 22
Supernovae, neutron stars and black holes 23
Worked examples: stars and black holes 24
Quick check: stars 25
Cosmology
The Doppler effect and red shift 26
Hubble’s law and the Big Bang 27
Quasars 28
Detecting exoplanets 29
Worked examples: cosmology 30
Quick check: cosmology 31
Reference
Equations for Paper 3 32
Exam checklist 33
Paper 3 revision notes · 2
,REFERENCE
Using this pack
How the pack works
Paper 3 is a 2 hour written paper, 80 marks, 32% of the A level. Section A (45
marks, compulsory) tests practical skills and data analysis; Section B (35 marks)
tests one option topic - this pack covers Astrophysics (section 3.9 of the AQA 7408
specification).
If your school teaches a different option (Medical physics, Engineering physics,
Turning points in physics or Electronics), Section A of this pack still applies to you
in full.
Each topic has colour-coded notes, worked examples with every step shown, and
quick-check questions with answers.
The last pages hold the 12 required practicals, an equation list and an exam
checklist. Assumed knowledge from Papers 1 and 2 can appear anywhere.
Constants used in the examples
Gravitational constant G 6.67 × 10⁻¹¹ N m² kg⁻²
Speed of light c 3.00 × 10⁸ m s⁻¹
Stefan constant σ 5.67 × 10⁻⁸ W m⁻² K⁻⁴
Wien constant 2.9 × 10⁻³ m K
Hubble constant H 65 km s⁻¹ Mpc⁻¹
1 parsec 3.08 × 10¹⁶ m (≈ 3.26 light years)
1 light year 9.45 × 10¹⁵ m
1 Mpc 10⁶ pc
Solar mass M☉ 1.99 × 10³⁰ kg
Solar radius R☉ 6.96 × 10⁸ m
1 year ≈ 3.16 × 10⁷ s
Rounding
Carry full calculator values through a calculation and round only the final answer to
the same number of significant figures as the data (usually 2 or 3).
Paper 3 revision notes · 3
, PRACTICAL SKILLS AND DATA ANALYSIS
How Paper 3 Section A works
The paper at a glance
Paper 3 is a 2 hour written exam, 80 marks, 32% of the A level.
Section A (45 marks, compulsory): short and long answer questions on practical
experiments and data analysis. Any of the 12 required practicals can come up,
often in an unfamiliar context.
Section B (35 marks): short and long answer questions on your option topic. This
pack covers Astrophysics (specification section 3.9).
Assumed knowledge from the whole specification can appear in either section.
What the questions are really testing
The examiners call these practical skills PS1 to PS4. In plain words they want you to:
Solve problems in practical contexts - apply physics you know to an experiment
you may never have seen.
Comment on and improve experimental design - variables, control, resolution
of instruments, safety.
Present and analyse data - plot and interpret graphs, process results, use log
graphs.
Evaluate results - judge accuracy and precision, use uncertainties, draw justified
conclusions.
Know the instruments - micrometers, verniers, stopwatches, multimeters,
oscilloscopes, light gates, data loggers.
Command words
Describe/Explain - say what and why, in order. Determine - use the data to get a
value with a unit. Show that - give every step and end with at least one more
significant figure than the target. Evaluate - judge with evidence from the data.
Paper 3 revision notes · 4
